An alternative Royal Navy for the 1970s

[Grey Havoc]

In London, you had the Isle of Dogs which would have provided land for a dedicated heliport. Other cities had such areas of land which were no longer being used for their original purpose. However, you're concentrating on Western Europe. In Asia, the Rotodyne would have found considerable use, while Downunder it could have also been used as a regional airliner. In the US, a similar situation existed. Plenty of tall buildings with flat roofs there! In Western Europe it's greatest enemy would have been the VFT.

Even in smaller cities, the multi-storey car park makes pretty much an ideal vertiport: bus station on the bottom, car parking in the middle, helicopters and VTOLs on top. Easy enough to implement, but doesn't do anything to get around the economic difficulties of VTOL operations.

IMHO, a smaller Rotodyne in the Gannet/Sea King size class, with a twin Mamba or similar, would have been ideal - reasonably large market for ASW and transport, both roles which would benefit from a Rotodyne. An attack variant to the AAFSS requirement would be rather interesting.

Your discussion reminded me of this little gem of 1957 vintage:

http://www.secretprojects.co.uk/forum/index.php/topic,2504.msg205729.html#msg205729

 

[Tony Williams]

The tactical benefits of VTOL for military use has never really been proven

Pardon? I don't think you can have meant what you said, given the vast numbers of military transport helicopters which have given invaluable service in many theatres.

 

[Abraham Gubler]

The RN were offered and considered the Vickers 4" and were unimpressed from a technical perspective, the file still exists at Kew.

Compared too many weapons ‘around’ (as in proposed, under development, recently cancelled, coming into service, etc.) at that time (1953) it is rather unimpressive. But therein lies its charm. It is a relatively simple mounting to install on a ship but can still spit out a lot of big 4” shells. And the mount that reached fleet service was a fair bit better than that originally proposed. Which is a movement of quality in direct opposition to most other guns of this era.

The big thing, apart from shooting around twice as many shells than the 4.5 inchers, is that it is much easier to install on a ship than the Mk 6 4.5” mounting. It doesn’t need the large gun room below decks which frees up a lot of volume and usually un-tabulated weight. The mounting is also half the above decks weight (and far less below) than the Mk 6 and importantly tops out (turret roof) at only 10’ above deck compared to 12’. The later means that the famous cranked sheer of the forecastle of the Types 12, 41, 61 and Leander frigates can be slightly less deep allowing for a higher deck height under the gun mounting. This is nice for the head room of the sailors but significant for later days when the RN replaces that Mk 6 4.5” gun with the Ikara system on a flotilla of its Leander frigates. The extra head room would enable the Type 82 Ikara installation to be installed without the need for a costly new magazine and handling design.

The savings in top deck weight thanks to the 4” gun on such ships could enable better and more secondary weapons, radars and helicopter arrangements. The additional space below decks could be used for the rooms needed to operate these things.

 

[Abraham Gubler]

The problem of course (apart from the 3" technical issues) was that while great for AAW, the 3" was poor at surface warfare and NGFS.

This is an assumption that too many (myself included) seem to hold. The 3” L70 shell (even better than the common OTO gun 3” L62) firing at high rates of fire is a very effective naval gun for surface warfare and shore bombardment. That is very effective at the greater majority of likely encounters rather than the handful of now (and then) obsolete encounters that dominated assessment. Yes the lightweight 3” shell (6.8 kg, 15 lbs) is not going to make much of a scratch on a gun wagon like the Soviet Sverdlov class but against other destroyers it would be lethal. Because of the high rate of fire and high number of hits spread across the cross section of the target ship it would literally rip the enemy ship to pieces. This used to be called the “hail of fire” way of sinking ships until the Dreadnaught made it obsolete. But since the 1950s it’s a post Dreadnaught world and this approach via a gun system with equal range (3” L70 can match and exceed 4.5” in time of flight) is a far better way to achieve target defeat. Of course such a high rate of fire weapon is far more capable against high speed, small targets like torpedo and missile boats which were increasingly the surface threat in the 1960s and later.

As a NGS weapon the 3” high rate of fire mounting gets the most flak. But in the majority of NGS missions (including those fired in VietNam and the Falklands) it is far better than slower shooting medium calibre guns. These are suppression missions fired at mobile coast guns without overhead protection, infantry and airfields. In this case the lighter shell of the 3” is more than made up for with the rapid rate of fire and inherent VT fusing in each round. The Mk 6 3” gun can put down a weight of air bursting or PD high explosives at 3.25 times the rate of the MK 6 4.5”. Since the generation of effective splinters is not at direct proportion to shell rate but rather weighted against increasing shell size the comparable frontages (area saturated by artillery splinters) of the 3” would be even higher than x 3.25 compared to the 4.5”. Likely to be around 4-5 times a greater frontage per gun mount. And with a fully mechanical loading system for the first 320 rounds and barrel cooling this rate of effort can be sustained without reliance on the physical state of the crew, the heating of the barrels and the effect on them of the local weather.

The only thing the 3” lacks compared to 4-5” shells is less ability to destroy protected targets like emplaced guns (with overhead protection) or armoured vehicles (requiring the heavier splinters of the larger shells to defeat their armour). But most operational experience has shown that 4-5” shells are ineffective against these types of targets too. Heavier 6-8” shells are needed to defeat protected targets. The high rate of fire of the 3” gun actually gives it an advantage compared to 4-5” guns in use against protected targets. If such a target is actually within direct line of sight of the ship it can be engaged directly. The high rate of fire of the 3” allows for much better accuracy and a direct hit onto the gun shield of an artillery system or an AFV by such a round is far more effective than the damage caused by nearby detonations of statistical weapons with realistic shell sizes (4-8”). Whilst the 4-5” gun lacks the rate of fire to score a direct hit and the shell weight to cause damage via statistical bombardment.

Since the Falklands War seems to be the benchmark used here frigates with the Mk 6 3” would not only be able to hack Daggers and Skyhawks out of the air but also be better placed to provide withering suppressive bombardments of Argentine field positions and the airfield base area.

 

[Abraham Gubler]

In Asia, the Rotodyne would have found considerable use, while Downunder it could have also been used as a regional airliner. In the US, a similar situation existed.

In the crowded mega cities of Japan and in Hong Kong maybe yes. But however the small sector lengths of the city centre to anywhere important in these cities means these routes are far more economically and effectively served by smaller helicopters (and equally sized, ie Chinook).

In Australia and America there is even less need for a Rotodyne than in Europe. Both countries are big with widely distributed populations. This means the sector size is longer (distance between where people are and want to go) and airfields are easy to install (plenty of unused land for them). So in lands of abundant airfields and long flight distances why on earth (or hovering above it) would you want an aircraft that is slower, with much shorter legs, costing far more to buy and maintain and burning far more fuel just to avoid the runway fees?

 

[Abraham Gubler]

The tactical benefits of VTOL for military use has never really been proven

Pardon? I don't think you can have meant what you said, given the vast numbers of military transport helicopters which have given invaluable service in many theatres.

This is utility and assault transport. And yes the helicopter is better than the fixed wing aircraft (volpane anyone?) in these roles which is why there aren't large fleets of Short Brothers Skyvan utility aircraft and Airpseed Horsa assault gliders in service in Army Aviation Arms around the world.

But in intra and into theatre transport the domain is fully covered by the fixed wing airlifter. There are a few interlopers with IFR supported H-53s and V-22s but these are niche roles. Otherwise if you want to fly your stuff in and out of the warzone you need the range and payload efficiency that only fixed wings can give even if it does cost you being fixed to a klick or two of graded dirt or better.

 

[JFC Fuller]

Which seems to have been part of the issue; the 4.5" Mk.V gun in the Mk.6 mounting actually had approximately the same shell output (though with heavier shells) as the Vickers 4" single mounting, the only advantage was the mounting weight and that was offset by the fact that the frigates were essentially already designed (Leanders being evolution of the Type 12 design) and the existing gun system already in service. Additionally, as built the Leander's had everything the RN could afford to put on them anyway.

It would have made no difference to the magazine and handling design for the Ikara frigates which was determined by RN requirements for the Ikara system as much as by the frigates themselves.

 

[Abraham Gubler]

I've always felt Seacat 2 was a missed opportunity, might not have worked out that cheap, but you could use the same launcher so it was a lightweight system and potentially (with the right fire-control gear) could have boosted the defence of every Sea Cat equipped vessel in a way the heavier Sea Wolf never could.

The Seacat 2 missile (per unit) wouldn't have costed that much more than a Seacat "1". It achieved the far higher speed thanks to better design and still used the same basic components in similar sizes. The Seacat 2 would also use the same launchers and FCS in varying marks as the produced Sea Cat. Without a change to these the supersonic missile would have made a huge difference. Seacat's main shortfall in the Falklands was quite literally a shortfall. Due to the short response time available from TIR against sea skimming, cresting and pop-up targets most engagements were tail chases. In which case the Daggers and Skyhawks would have needed to fly at speeds below 400 knots to make interception possible (which they didn't!) before the Seacat ran out of energy and fell short. A supersonic version of the same missile would be able to overtake the strike fighter and engage it. Seacat guidance was considered more than adequate since the Argentinians only attacked in the day and its reliability was outstanding. Seacat 2 would have massacred the Argentinians. Even a <0.5 pK would have resulted in a doubling of the Argentine strike fighter losses and a complete destruction of their attack force (88 Daggers and Skyhawks, 33 shoot down, ~80 Seacats fired without effect).

Abraham's idea of an Ikara-sized Anglicised RBS-04 is an interesting concept too, it makes use of the Ikara launcher for more than one role although I suspect it might lead to magazine growth to stow enough missiles to enable a reasonable loadout for ASW and ASuW.

Not my idea. There were several proposals to develop anti-ship versions of the Ikara even before the development of the at-sea maintenance free Boxed Ikara (BOXIK) in the 1980s. But in one of those wonderful, hard to understand failure of priorities the only variant of Ikara pre BOXIK funded for serious development was the non-war use Turana target drone. Which would have made a perfect ASM as it first flew in 1971 and was powered by a Microturbo engine (no highly vulnerable to flak, high signature, danger to the ship rocket motor to power it unlike Exocet). If the Aust. DoD had the common sense to file ship launched target drones under the 'luxury to buy once you have a full arsenal of in service weapon systems' column and have built Turana with a ship seeking sensor and a 500 lb SAP warhead it would have been a world beater. However Turana came first and was to be followed by Woomba (a ASM version of Turana as described above) but it was (of course) cancelled due to budget cuts and the lack of success of Turana. Which was put down to a lack of communication between the Navy and the contractor (GAF). Why is no one surprised? The linkage with the RBS-04 is simply based on the Exocet-Kormoran linkage.

 

[Abraham Gubler]

Which seems to have been part of the issue; the 4.5" Mk.V gun in the Mk.6 mounting actually had approximately the same shell output (though with heavier shells) as the Vickers 4" single mounting, the only advantage was the mounting weight and that was offset by the fact that the frigates were essentially already designed (Leanders being evolution of the Type 12 design) and the existing gun system already in service. Additionally, as built the Leander's had everything the RN could afford to put on them anyway.

The Leander was redesigned from the Type 12 to allow for accommodation of the Mk 6 3" in place of the Mk 6 4.5" though it was not fitted. So if in place of this it was redesigned for the Mk N 4" and actually fitted as such it could accrue the advantages I listed above (which may not be realised at birth but since the Leander with Mk 6 consumed all of the Type 12's useful Board and accommodation margins much to the frustration of through life refits it is a pretty attractive advantage: restoring a design margin). The weight of shot is dependent a lot on what the Mk 6 4.5" actually produces. While weight of shot is comparable it doesn't take into account the advantages of higher rate of fire leading to higher hits. The Mk N could reliably shoot bursts of 16 rounds in 20 seconds. The Mk 6 could only reliably manage 8-10 rounds in a 20 second burst.

It would have made no difference to the magazine and handling design for the Ikara frigates which was determined by RN requirements for the Ikara system as much as by the frigates themselves.

Marland makes clear in "Warship 2015" the Leander Ikara conversion was hamstrung by the difference in deck heights between the Type 82 (for which the RN's Ikara M&H system had been designed). A Leander designed for the Mk N would not need such a high crank in the forecastle so allowing a higher height between 1 and 2 deck. In the Leander both decks were cambered with 7'6" between them. The Type 82 had a flat 2 deck with a cambered 1 deck between 8'6" and 8'9" above it. Assuming the forecastle deck was re-contoured between the Type 12 and the Leander (or earlier) to take into account the 2' of less height of the Mk N 4" turret this would enable the Leander deck height between 1 and 2 decks to be sufficient to enclose the original Ikara M&H system. Therefore avoiding the need for the deep magazine of the Leander conversions and the subsequent high cost of fitting such.

 

[JFC Fuller]

The Leander wasn't redesigned for the 3", it was an armament option in the design phase but dropped, the ships were designed with the 4.5". Weight of shell actually contributes to the probability of bringing down a target by resulting in larger blast volumes.

The choice of a deep Ikara magazine on the Leander's was driven by a lot more than deck heights, most notably by top weight issues associated with a radical conversion of a ship already at the edge of its margin. The 4.5" magazine put a lot of weight in the bottom of the ship, the best way of keeping that weight there following the removal of the gun was to put the Ikara magazine in the same location, even with that the Ikara conversions had to land their Type 965 radars.

 

[Tony Williams]

But in intra and into theatre transport the domain is fully covered by the fixed wing airlifter. There are a few interlopers with IFR supported H-53s and V-22s but these are niche roles. Otherwise if you want to fly your stuff in and out of the warzone you need the range and payload efficiency that only fixed wings can give even if it does cost you being fixed to a klick or two of graded dirt or better.

This is where circumstances alter cases. The big, long-range airlifters like the C-17 can technically use dirt runways but I understand that in practice the users don't like doing that - too easy to damage a very expensive plane which is only available in very small numbers (USAF apart). They also don't like putting them down anywhere that there is any chance of someone trying their luck with MANPADS. So they generally deliver into large permanent airbases well away from the combat zone - possibly too far for a helo to reach. So they may need to transship cargo into a C-130 or something which gets it to a dirt runway close enough to transfer it to a helo for the final stage. In such circumstances, a big gyrodyne could do the job of the C-130 and the helo.

The exact circumstances in each case will determine what the optimum combination of aircraft types will be, it's possible to argue it either way. But the US Army is currently taking a hard look at future vertical airlifters and is clearly looking for a better performance than conventional helos can manage: both tilt-rotors and compound helos are in the mix. A gyrodyne could have delivered such performance decades ago.

 

[zen]

Hmmm.....

Thoughts....while the 4.5" is virtually a 'given' considering it's heritage. The 3" would be an interesting concept to ponder on the Type 82, and Type 19 studies.

In fact it would free some margins on the earlier Countys too.

3" L70 is rather more than the current developments of 76mm L62 guns, if there is some lack of 'weight' in this shell, surely a alternative shell within the same dimensions could be investigated for hitting armoured targets?

I still do feel that while to field two guns in separate turrets is a greater cost and weight, the option of a single gun mounting would extend the ability to fit this weapon on a wider variety of ships. Ideally in place of the 40mm twin Bofors.

I don't have dimensions for Sea Cat II, but it does look approximately similar in size to Rapier on Tony Butlers book.
Sea Cat matched with MRS3 as I think GWS22 it was said to be quite potent. Would be an interesting stepping stone to have Sea Cat II and then upgrade to a compact digital successor to MRS5.
Shades of Rapier and PT.428.

Hmmm.....what does that do to the likes of Type 19 if we combine the two? After all during the process of coming up with Type 19 options the anti-fast boat mission was exerting some influence.

Also even on the Countys Sea Cat was considered a dubious extra at times, because of it's lack of capability.

Anti-ship versions of Ikara are an interesting option to ponder.
Question, could it even drop a torpedo at the targeted ship?

 

[Hood]

The tactical benefits of VTOL for military use has never really been proven

Pardon? I don't think you can have meant what you said, given the vast numbers of military transport helicopters which have given invaluable service in many theatres.

I was meaning concepts like Harrier, TSR-2 hoverpads, AVS, FW.1262 and other related VTOL ideas. But I agree that intra-theatre transport has been the domain of the fixed wing airlifter. Saying that, its notable that dedicated intra-theatre airlifters like the HS Andover, Caribou and the C-22J have had quite limited lifespans in bigger Western air forces like the RAF and USAF (and the related USAF/ US Army tussle on such aircraft). They tend to have stuck with C-130-size minimum forces, excepting France, Germany and Italy (relatively small nations and less overseas use) and the RAAF made the fullest use possible of the Caribou and have replaced like for like in the C-22J.
CV-22 always looks like being niche, Israel and Japan are more likely to use them for special forces and dedicated roles rather than tactical logistical airlift.


Regarding the use of the 4.5in Mk.6 for NGS. Some interesting points arise from Steven Paget's article 'On a New Bearing: The reorganized Royal Australian Navy at war in Vietnam' in the journal Mariner's Mirror.
HMAS Vendetta was the only Daring to operate off Vietnam and only made one deployment between September 1969 and March 1970. At other times the RAN used their new Adams Class destroyers, but for those few months only Vendetta was available. Paget states that despite Vendetta's age, "Nevertheless, the capacity of Vendetta's six 4.5-inch guns to fire up to one hundred rounds per minute in good conditions made her a valuable asset when NGS was required. In total, during the RAN commitment to Vietnam, the destroyers fired approximately 80,000 5-inch/54 and 6,800 4.5-inch rounds at a daily average of 115 rounds per day."
Interestingly Vendetta actually offered a useful variance in ammunition due to problems with the 5in/54 ammunition. Intermittently during 1971, HMAS Brisbane was limited to undertaking missions outside the range of 5in/38 armed ships due to difficulties with barrel wear and problems with the ammunition. The quality of 5in/54 cartridges seems to have been a constant concern, all firings had been suspended in April 1967.
Regarding the use of destroyers in the NGS role, Paget argues "by the end of 1970, DDGs accounted for 10 per cent of NGS missions and only 11 per cent of the rounds expended during those firings. While the number of firings was limited, the ships were essential for extended range shoots when cruisers or battleships were unavailable. Tellingly, DDGs were responsible for 34.2 per cent of Sea Dragon missions, which often required an extended range capability."

 

[Abraham Gubler]

The Leander wasn't redesigned for the 3", it was an armament option in the design phase but dropped, the ships were designed with the 4.5".

Yes but the incorporation of the 3” as an option required a redesign of the ship hull and bow from the baseline Type 12. One outcome of this was the removal of the bow diesel generators. This factoid was raised to refute the argument that designing the Leander to incorporate the 4” mount would be extra effort and therefore unlikely despite whatever advantage may accrue. The effort to redesign the bow so 3” could be fitted could have been used to redesign the bow for 4”.

Weight of shell actually contributes to the probability of bringing down a target by resulting in larger blast volumes.

But not in direct proportion to the increase in shell weight. The law of diminishing returns applies. The usual measure for shell effectiveness in AA is the bursting charge. As this determines the lethality of the splinters generated if steel is of equal quality. The difference between a 4” and 4.5” is minimal. But increased weight of fire does not just contribute to equalising total weight of shellfire. But importantly it increases accuracy via the adjust fire principle. The quicker you can shoot shells the more you can improve accuracy by noticing the distance of each miss and consecutively adjusting for this variation. And the smaller the target’s vector can vary between shots and therefore diminish the value of adjusting fire. This is the principle reasons the Mk 6 3” was so accurate, especially when combined with radar guided and computerised fire control. Not that is fired a great mass of shells into the air creating a “wall of steel” but that there was 1/3 of a second between each shot and the FCS was able to quickly bring the line of fire within the lethal distance of the target’s vector and therefore shoot it down.

The choice of a deep Ikara magazine on the Leander's was driven by a lot more than deck heights, most notably by top weight issues associated with a radical conversion of a ship already at the edge of its margin. The 4.5" magazine put a lot of weight in the bottom of the ship, the best way of keeping that weight there following the removal of the gun was to put the Ikara magazine in the same location, even with that the Ikara conversions had to land their Type 965 radars.

True. It was a long bow to draw for a specific outcome. But the benefit of the restoration of the life of type margin to the design is significant for the ship. Combined with a better gun for AAW and SuW fire and no appreciable loss of NGS capability it’s a win-win situation. Especially as it defrays later expenditure on the Mk 8 4.5” and allows for supplanting the obsolete Mk 5 4.5” on the Tribals and provides an interesting option for the County class.

 

[Abraham Gubler]

This is where circumstances alter cases. The big, long-range airlifters like the C-17 can technically use dirt runways but I understand that in practice the users don't like doing that - too easy to damage a very expensive plane which is only available in very small numbers (USAF apart). They also don't like putting them down anywhere that there is any chance of someone trying their luck with MANPADS.

I’m pretty sure the 100-200 Army guys sitting in the back of the C-17 agree with that safety assessment by the Air Force aircrew.

The exact circumstances in each case will determine what the optimum combination of aircraft types will be, it's possible to argue it either way. But the US Army is currently taking a hard look at future vertical airlifters and is clearly looking for a better performance than conventional helos can manage: both tilt-rotors and compound helos are in the mix. A gyrodyne could have delivered such performance decades ago.

The possibility of this argument is only entertained when the gyrodyne is given range performance it doesn’t have. What is possible today with the JHX demonstrator is only realistic thanks to 50 years of gas turbine, gearing, flight controls and aero structure developments. With 1950-80s technology VTOL airlifters just aren’t competitive because they can’t carry the payload and the fuel to make them useful.

 

[Abraham Gubler]

Regarding the use of the 4.5in Mk.6 for NGS. Some interesting points arise from Steven Paget's article 'On a New Bearing: The reorganized Royal Australian Navy at war in Vietnam' in the journal Mariner's Mirror.

The quest for range during SEA DRAGON was something my memory overlooked in formulating the arguments above. This was a very specific requirement caused by the mass supply to the NVA of 130mm coast artillery by the Soviets. Even the 5” L54 lacked the range to engage the 130mm outside of its danger zone and the USN looked at some range extension technology that was to be later realised. However you could take on the 130mm with shorter range 5” L38 and 4.5” guns because you were moving and they were not. At long ranges even the 130mm suffers from dispersion.

HMAS Vendetta was the only Daring to operate off Vietnam and only made one deployment between September 1969 and March 1970. At other times the RAN used their new Adams Class destroyers, but for those few months only Vendetta was available. Paget states that despite Vendetta's age, "Nevertheless, the capacity of Vendetta's six 4.5-inch guns to fire up to one hundred rounds per minute in good conditions made her a valuable asset when NGS was required. In total, during the RAN commitment to Vietnam, the destroyers fired approximately 80,000 5-inch/54 and 6,800 4.5-inch rounds at a daily average of 115 rounds per day."

The Daring class could run the risk of opening up with all (or two) mountings using the power rammers (to achieve the high rate of fire) because it had redundancy. If one of the mounts jammed it had the other two to keep shooting. Ships with single Mk 6 4.5” turrets like the Type 12s and Leander’s did not have this luxury. A jammed gun takes out 50% of their fires and a mounting breakdown 100%. Much better to take the cut in rate of fire with the Mk 6 to ensure you could still keep shooting through the engagement.

The Vendetta’s big advantage over the Charles F. Adams DDG and most other USN DDs in the fleet at the time was it had three mounts vice two. So it could shoot with two mounts and keep the third in reserve. So if a mount or gun broke down or had a misfire the third mount could swing into action and sustain the fire mission without the NGOs on the sharp end noticing a falloff in rate of fire. The broken or dud mount can be returned to action and then become the back up to the other two mounts.

 

[Abraham Gubler]

They tend to have stuck with C-130-size minimum forces, excepting France, Germany and Italy (relatively small nations and less overseas use)

If you are referring to the French and German use of the C-160 Transall it is the same size as the C-130. Just has two bigger engines in place of four big engines. The payload and range differences between the two are marginal.

and the RAAF made the fullest use possible of the Caribou and have replaced like for like in the C-22J.
CV-22 always looks like being niche, Israel and Japan are more likely to use them for special forces and dedicated roles rather than tactical logistical airlift.

The RAAF's use of the Caribou post VietNam War has been dominated by two divergent requirements. PNG and NW Australia flights that required low logistical infrastructure (short runways and AVGAS in drums) and the infil/exfil of special forces (SASR). The first requirement is now redundant thanks to the subsequent appearance of a large commercial aviation sector in the PNG and NW Australia supporting the mining industry. The second requirement has on the other hand been boosted by the Global War on Terror. The C-27J is very much about flying in and out SASR vehicle patrols to behind enemy lines or other places they aren't meant to be.

 

[Tony Williams]

The possibility of this argument is only entertained when the gyrodyne is given range performance it doesn’t have. What is possible today with the JHX demonstrator is only realistic thanks to 50 years of gas turbine, gearing, flight controls and aero structure developments. With 1950-80s technology VTOL airlifters just aren’t competitive because they can’t carry the payload and the fuel to make them useful.

In its day, the Rotodyne was greatly superior to any other form of VTOL transport, and if it had "taken off" and become an established technology, then today it would also be benefiting from 50 years of technical development.

 

[JFC Fuller]

The Leander class were not designed for the 3" gun, it was considered in pre-Leander concepts (1959) but had a notable impact on ship length and displacement and was not carried through to the final Leander design which used the Type 12 hull form. The diesel generators that had been located in the forecastle on the Type 12 class were relocated to just forward of the boiler room on the Leander class because the elimination of the separate ballast tanks freed up space to allow it and it was something that had always been highly desirable, 1950s technology diesel generators being heavy and therefore ideally located in the lower centre of the ship where they would have a less negative impact on stability.

The Vickers 4" was not really a superior AA weapon at all, it managed 40 rpm (as advertised by Vickers, and apparently what was actually achieved practically) versus 32 rpm for the Mk.6 twin 4.5 inch mounting. Given the very significant difference in shell weight between the two guns (32lbs versus 55lbs) the Mk.6 twin mounting was a much better ASuW and NGFS weapon. This was exactly the conclusion the RN themselves came to when Vickers offered them the 4" gun.

 

[Rickshaw]

The possibility of this argument is only entertained when the gyrodyne is given range performance it doesn’t have. What is possible today with the JHX demonstrator is only realistic thanks to 50 years of gas turbine, gearing, flight controls and aero structure developments. With 1950-80s technology VTOL airlifters just aren’t competitive because they can’t carry the payload and the fuel to make them useful.

In its day, the Rotodyne was greatly superior to any other form of VTOL transport, and if it had "taken off" and become an established technology, then today it would also be benefiting from 50 years of technical development.

A factor which gets overlooked all too often when discussing Rotodyne, IMHO. The Rotodyne of today would be comparable or superior to the V-22 of today.

 

[Abraham Gubler]

The possibility of this argument is only entertained when the gyrodyne is given range performance it doesn’t have. What is possible today with the JHX demonstrator is only realistic thanks to 50 years of gas turbine, gearing, flight controls and aero structure developments. With 1950-80s technology VTOL airlifters just aren’t competitive because they can’t carry the payload and the fuel to make them useful.

In its day, the Rotodyne was greatly superior to any other form of VTOL transport, and if it had "taken off" and become an established technology, then today it would also be benefiting from 50 years of technical development.

A factor which gets overlooked all too often when discussing Rotodyne, IMHO. The Rotodyne of today would be comparable or superior to the V-22 of today.

Yet thanks to the one way movement of time none of that helps the Rotodyne back in 1960. Just as there was no in-service tilt rotor in the 50s, 60s and 70s there was no in-service tip jet powered compund helicopter-auto gyro. The only argument this realisation supports is that a clean sheet, appropriately sized Rotodyne could have been a reasonable prospect for the JVX/V-22 program. But that's some 40 years too late for Fairey and Westland.

 

[Hood]

It's a double-edged sword argument.

One only has to compare the development of the Chinook to see what progress in design, components and structures can achieve:
1962: CH-47A, initially 2,200hp Lycoming T55-L-5 engines (later 2,650hp T55-L-7 or 2,850hp T55-L-7C), maximum gross weight of 33,000lb (15,000kg) max gross weight, 10,000lb (4,500kg) payload.
2006: CH-47F, 4,733hp Lycoming T55-GA-714A, 50,000lb (22,680kg) MTOW (Block 2 would be 54,000lb (24,500kg)), 28,000lb (12,700kg) payload.
Yet its clear the market for a Rotodyne equivalent-sized fixed-wing tactical transport of that size has diminished over the years (Andover went in 1975 after just 9 years in service).
Without a market such an arguement is pure conjecture, for example; "In its day, Concorde was greatly superior to any other form of SST transport, and if it had "taken off" and become an established technology, then today it would also be benefiting from 50 years of technical development." Yet Concorde (and SST) is now a museum artefact.


Getting back to naval matters; how plausible would an Olympus & Tyne COGAG plant be for Type 82? I feel it might have been slightly too early to go down that route and with other novel systems on board it would have increased risk and cost, but I'd like to hear others opinions on the subject. Would an all-steam powerplant (a twin Leander plant) be better?

 

[Tony Williams]

Yet thanks to the one way movement of time none of that helps the Rotodyne back in 1960. Just as there was no in-service tilt rotor in the 50s, 60s and 70s there was no in-service tip jet powered compund helicopter-auto gyro. The only argument this realisation supports is that a clean sheet, appropriately sized Rotodyne could have been a reasonable prospect for the JVX/V-22 program. But that's some 40 years too late for Fairey and Westland.

Well, this is meant to be an alternative history section to consider "what ifs", and my speculation is based on the orders for the Rotodyne not having been cancelled, and the planned acquisition by the US Army kick-starting a continuing future for the gyrodyne concept.

Yet its clear the market for a Rotodyne equivalent-sized fixed-wing tactical transport of that size has diminished over the years (Andover went in 1975 after just 9 years in service).
Without a market such an arguement is pure conjecture,

I don't see the Rotodyne as having been primarily a rival to military fixed-wing planes, but as a competitor to helicopters, offering far more performance.

 

[Hood]

The dates are the tricky part, and probably part of the reason COGAG wasn't selected.
Bristol was ordered in October 1966 and laid down November 1967, so the design would have to been firm by then and trials were still two years away, so it would have been too late to redesign from COSAG to COGOG. Of course the decision could have been made in 1963, but I suspect range drove the initial decision, Design 53G (the all-gas comparison to the steam-powered 53A) had a 1,000nm range penalty.

An all-gas Type 82 would have some room for further growth or a slightly faster lighter ship. The COSAG was 30,000shp steam plant and 2x Olympus for 30,000shp; the Olympus TM1 was rated for 24,000shp giving 48,000shp but two 3,500shp Proteus 10M for cruising would be probably be too low powered for a ship that size (Type 42 with two later 5,340shp Tyne RM1C made 18kts, for example).

I don't see the Rotodyne as having been primarily a rival to military fixed-wing planes, but as a competitor to helicopters, offering far more performance.

I think it was a tightly fought three-way contest with everyone looking at entering that area, in 1959 de Havilland Canada felt the Caribou was "in competition with the freight helicopter which, at present, shows about the same field performance when fully loaded." https://www.flightglobal.com/pdfarchive/view/1959/1959%20-%203033.html?search=Caribou
I think Rotodyne faced its toughest competitors from fixed-wing, for military users it had to show it was a worthwhile addition to existing fleets tactical transports and perform better than the big civil helicopters in airline use, like the Vertol V-44 (I can only think of SABENA's use of the V-44 for such types used in Europe during the 1957-62 timeframe).

 

[Abraham Gubler]

Well, this is meant to be an alternative history section to consider "what ifs", and my speculation is based on the orders for the Rotodyne not having been cancelled, and the planned acquisition by the US Army kick-starting a continuing future for the gyrodyne concept.

Of course the point of contention being the realism or lack there of in such speculation. If you don't want to hear these other opinions and the facts and analysis that underpin them then don't post you speculation here asking for feedback.

As has been pointed out the lack of performance of the Rotodyne makes it hard to see how it is going to become a world beater even if it was introduced into service in the initial proposed orders.

I don't see the Rotodyne as having been primarily a rival to military fixed-wing planes, but as a competitor to helicopters, offering far more performance.

That performance comes at a huge cost and it is in an operational class for which the need just didn't exist at the time. In the 1960s the only VTOL performance categories that the Rotodyne stood out in was the abortive ASW with huge dipping sonar and CSAR. As a CSAR platform it offers great performance but its huge size and large areas of vital plumbing would raise very significant questions about its survivability in the face of trash fire. The cargo helicopter missions of the CH-47 and CH-53 did not require the long range of the Rotodyne.

Since the Rotodyne comes at a much higher cost to buy and operate than these helicopters its hard to see this "vision" as being more than just hallucination.

 

[Tony Williams]

Of course the point of contention being the realism or lack there of in such speculation. If you don't want to hear these other opinions and the facts and analysis that underpin them then don't post you speculation here asking for feedback.

Since the British placed an order for a dozen military versions and the US Army expressed an interest in 200 of them (all torpedoed by the unsurprising failure of the civilian concept), some people obviously saw a military application, so speculating what might have happened if this had been followed-through does not involve any hallucinations.

 

[Grey Havoc]

...The cargo helicopter missions of the CH-47 and CH-53 did not require the long range of the Rotodyne.

Those personnel who were involved in Operation Eagle Claw, for example, might disagree with you there.

 

[Abraham Gubler]

...The cargo helicopter missions of the CH-47 and CH-53 did not require the long range of the Rotodyne.

Those personnel who were involved in Operation Eagle Claw, for example, might disagree with you there.

Probably because they were flying an aircraft not designed for the mission. But it could have been right? Is that what you are suggesting? Next time you travel back in time go tell the marines in 1960 that their Deuce replacement needs very long range so as to fly from Oman to Tehran to rescue the US embassy personnel who have been taken hostage by uni students. See how far you get with that.

 

[Hood]

I don't want to hijack Tony's alternate navy, but this thread has inspired me to do some thinking around the Type 82 and what an all-gas version cut down for economy and focused on air-defence might look like given the common strands most of us have discussed regarding armament options.

This is my what-if ideal Type 82 design.

My ramblings began with a basic what-if; move the Sea Dart forward and replace it with a hangar for 3x Sea Kings. Scaling from HMS Tiger showed Bristol's helideck to be almost the same length as Bristol's quarterdeck, a large hangar located at the forecastle break would also fit, flush with the hull sides. From there I began a fresh sheet design, paring back the barest essentials to get a decent air-defence destroyer of modest cost without the flagship extras and relying on helicopters as its ASW element.

Dimensions: 435ft 6in (oa) length; 55ft beam; 21ft draught (over sonar dome), 16ft (hull). Bigger than Type 42 Batch I but smaller than County, Type 82 and 42 Batch III.
Machinery: Two 24,000shp Olympus TM1 giving 48,000shp plus two 3,500shp Proteus 10M for cruising. Two Proteus seems insufficient for cruising, Type 42 with two later 5,340shp Tyne RM1C made 18kts for example. Other ideas are four Tynes coupled if such an arrangement could work with an Olympus on the same shaft. I think Type 82 is just slightly too early for marine Tynes.
Speed: 30kts (deep and clean)
Displacement: 4,500-4,750 tons standard, my ball-park estimate
Armament:
1x2 3in L/70 Mk.8, in this scenario the RN keeps the 3in L/70 and fits it instead of the 4.5in Mk.6 in frigates. I have designed a 'Mk.2' mounting with an unmanned GRP mounting which should be lighter and would incorporate a few changes to boost reliability, not so good for the anti-ship role, but in her role as an air-defence ship they can knock-down incoming aircraft as an inner layer of defence. Control by Type 909 over forward arcs or the two MRS-3 GWS-22 directors aft which should have ok arcs forward and aft for a three-channel control.
2x1 20mm Orkileon
1x2 Sea Dart SAM (38 missiles), fire-control by two Type 909
2x2 Sea Cat 2 SAM (36 missiles), fire-control by two MRS-3. The supersonic Sea Cat development goes ahead in this scenario as a cheap supersonic SAM which uses all the existing elements (launchers, fire-control) of the GWS-22 Sea Cat. Offers a good close-range SAM system to deal with leakers and is backed up by the 3in gun. I'm not totally happy about shipping two of the older MRS-3 but I envision a newer director for the 1970s or even replacement with Confessor.
2x Sea King or Wessex helicopters. My Type 82 is not a general purpose design as such, she is not optimised for anti-submarine warfare to save money for Ikara equipped helicopters. Soviet SSNs and SSGs and SSGNs are the main threat, stand-off missiles can be dealt with by the SAMs and guns. Any ASW weapon needs range and speed, what's better than a large Sea King? Superior to MATCH Wasp and Ikara won't fit this hull anyway. No Limbo, if an SSN is that close then the carrier you're protecting is in big doo-doos anyway. Also, sonar cut back to just the Type 184.
Radars: Electronics as the real Type 82, except one change. An off-shoot of the NIGS programme the New Surveillance Radar, what this was in real-life is still an unknown. In my scenario its the culmination of the ASWE is a single-rotating array 3-D radar equivalent to the SPS-52. Small and lighter than Type 988 and probably more achievable too.

The end result is very Type 42-ish, I admit I had one eye on that type as I sketched this out, but I think it looks less 'bloated' than Bristol which had a very strange superstructure layout compared to other post-war designs.

 

[Tony Williams]

I don't want to hijack Tony's alternate navy, but this thread has inspired me to do some thinking around the Type 82 and what an all-gas version cut down for economy and focused on air-defence might look like given the common strands most of us have discussed regarding armament options.

Looks interesting - certainly strong on the AAW.

Sea Dart did of course have some anti-ship capability (they could presumably have modified the fuzing to include an impact mode if needed).

Possible solutions to engine issue: three shaft, each with one Olympus - feather the outer ones when cruising; or just two Olympus and run only one shaft in cruising.

 

[zen]

Interesting scenario Hood!

Sea Cat II and a single 3" L70 would make for some interesting alternatives for Frigates and Sloops. Coupled with a faster move to all-GT powerplants.
But it does rather hijack the thread.
Perhaps one should start such a thread on the effect of these, starting presumably with the single 3"?

 

[Abraham Gubler]

Sea Dart did of course have some anti-ship capability (they could presumably have modified the fuzing to include an impact mode if needed).

Sea Dart and the missile & handling rooms for it designed to have a changeable nose for surface to surface firings. Details in Warship 2015.

 

[JFC Fuller]

For clarification, the Warships 2015 piece states that "early sketches" allowed for the warhead to be changed in the missile check room to a SAP warhead, I have never seen any evidence that such a capability made it into the systems actually built.

On a somewhat related note there is a closed file (retained by the MoD) listed by the National Archives and dated 1966 with the title "Proposal for a nuclear warhead for the SEA DART surface-to-air guided missile".

 

[Volkodav]

Very interesting topic that fits something I have been working on, a Type 42 with US combat system and weapons (Mk-13 and Mk-45) as well as a much larger hanger for a Seaking. May complete it as a midlife update with CEAFAR and possibly an 8 cell Mk-41, stuffed the paintjob so it is someway from finished so who knows.

Reading through the topic I am wondering what would have been involved in designing Sea Dart to fit the Mk-13. Obviously this would only have been feasible if the RN had adopted Tartar in the 60s. The system was looked at for some of the GW series cruisers, Escort Cruisers, Tribals, GP frigates, Battle and Daring MLUs; it is conceivable that had a number of these proposed fits gone ahead it may have been worthwhile license manufacturing the system in the UK for local and limited export use. This in turn would have made a UK upgrade path for the system viable, including being able to offer a new missile and FCS to existing Tartar operators.

I've been thinking on how to fit Ikara in a VLS or even a Tartar launcher and it struck me that while not an option for Ikara, Super Ikara would be interesting to reconfigure. Its rocket motor was used as the basis of that in Nulka decoy hence was adaptable to vertical launch and it was a contemporary of the DSTO Kerkanya glide bomb which has very compact folding wings. Its guidance package (much of which apparently ended up in the Milos ASW missile) could have been repackaged to fit on the nose, the motor on the back and the wings fitted to the body, creating a much more versatile and usable configuration for the 80s.

 

[zen]

Well the RN wanted Tartar with a UK devised Q-band seeker, rather than US X-band (or was it G-band I forget).

 

[Abraham Gubler]

Reading through the topic I am wondering what would have been involved in designing Sea Dart to fit the Mk-13. Obviously this would only have been feasible if the RN had adopted Tartar in the 60s.

Mk 13 compatibility maxs out at:

680 kg (1,500 lb) Weight
34.3 cm (13.5 in.) Diameter
4.73 m (186.0 in.) Length

Sea Dart is much wider with a 44cm (17”) diameter. This equates to a 1/3 reduction in frontal area to fit into the Mk 13 max width. Since its length is about the same as the maximum length of the Mk 13 you can’t compensate for your volume via a stretch. Not that you probably could because it’s a ram jet and needs that width to make its motor work.

Probably be easier just to replace the Sea Dart GMLS with a grown Mk 13 style system. Mk 13 has a very high density thanks to its efficient design. Mk 13+ sized for Sea Dart should have the same depth below deck but the diameter of its tub be increased from 16’ to about 22’. Which is a lot easier to fit into any warship than the big Sea Dart box located three decks down below the launching arm.

I've been thinking on how to fit Ikara in a VLS or even a Tartar launcher and it struck me that while not an option for Ikara,

The Ikara missile body can fit in the MK 41 VLS canister, just. These canisters are about 27” high by 27” wide. The Ikara is about 26” high by 15” wide. So if you had folding wings to fit within the 6” of space on each side you’ll good to go. Ikara had its beacon system in the vertical tail but no doubt a Mk 41 vertically launching Ikara would have a more advanced guidance system so not need any of that. Or be able to easily repackage that kind of stuff into the airframe in space vacated via the avionics refresh. Without the big vertical tail Ikara could easily be held inside and launched from the canister via a dorsal rail.

Shame the BOXIK was repackaged for VLS. When Sea Lance fell over it could have been a contender.

 

[zen]

It's hard to see a launcher being built just for Sea Dart, I think it would be more strongly justified if there was other weapons that could fit into said launcher, which cannot fit into a standard mk13.

However......in terms of wingspan
Exocet is 43" (1.1m)
Harpoon is 36" (0.91m)

Theoretically one might produce an Ikara with folding wings and tail that might fit down a reasonable size too.

 

[Volkodav]

Then again wasn't Typhon MR meant to use a scaled up Mk-13, depending how much work had been done prior to cancellation the may have been a reasonable start point available.

 

[zen]

Hmmmm.... Thing is Typhon LR is over 5ft span and over 2,000lb in weight. That said a launcher with that size of cell could hold an Otomat/Tesseo.

 

[Abraham Gubler]

Hmmmm.... Thing is Typhon LR is over 5ft span and over 2,000lb in weight. That said a launcher with that size of cell could hold an Otomat/Tesseo.

The high span of the Typhon is mostly associated with the booster rocket fins. These could easily be folding. Also the span of the fins and wings is usually inter-meshed with the arms that hold the missile in the handling gear. So often that space needs to be there anyway so as to move the missiles around. The Typhon missile body itself has a diameter of 18" (47cm) so a Sea Dart would fit nicely inside this footprint.

However I'm pretty sure the Typhon LR missile (RIM-50) was to be fired from a horizontal storage, Terrier style magazine and launcher. Typhoon MR (RIM-55) was to be fired from the Mk 13 launcher but it had the same dimensions as the Tartar missile (ie SM1-MR).