US 1950s Patrol Escort Project

[Hood]

I've asked the helpful folks over at Warship Disscussion 3.0 about this and despite much searching no-one could find any references, not even from Friedman's US books.

Reading Norman Friedman's 'British Carrier Aviation' he mentions the American Patrol Escort (PE) idea of the 1950s. Basically it was a "large Frigate" carrying six helicopters to search the Soviet submarine holding areas in the Mid Atlantic. He mentions it during the chapter about the British Cruiser Escorts and Through-Deck cruisers, so this may hint at the PE having a similar layout/role.

Were these to operate full helicopters or DASH? I'm thinking more of the latter myself if the ship is a frigate (I'm thinking along the lines of a bigger Coontz Class type but I might be wrong). The fact it is not classified a carrier hints at normal Frigate (what became DDG were classifed as Frigates during the mid 1950s) armed with ASROC and SAMs etc and during this time the Essex Class were serving as anti-submarine carriers anyway. Was this like a Moskva? Was there any rationale for such a ship given the Essex Class or was it a way to fund extra carriers for the Navy while Congress they were just Frigates?

Any help or information most welcome.

 

[shaba]

from what i have heard the helos where dash and the ship was related to the coast guard 210s.

 

[Yellow Palace]

I wonder if this corresponds to either the CVHG 'barrier escort' or the Terrier-armed PBG mentioned briefly in US Aircraft Carriers? as being considered in the mid-late 1950s. Unfortunately details of these aren't given, and it's not clear that the PBG was to be helicopter-capable. The helicopter to be operated from the CVHG (as well as the CVHE and CVS) was envisaged with a (presumably dipping) sonar of 10,000 to 20,000 yards, which certainly means a large, crewed helicopter rather than DASH.

In the case of the former, the USN seems to have used the CVHG term for the Soviet KIEV class, and the UK's INVINCIBLE class were ultimately referred to as CVSG (after a period as variously CAH and CCH). That would suggest to me a rather larger ship than just six helicopters. The contemporary CVHE was envisaged as being converted from surplus CVL and CVEs, implying that the CVHG would be of broadly similar capability but with guided missile (and air control) capability.

The numbers of ships involved - either 12 or 24 CVHG, the text is unclear, and 60 to 80 PBG - suggest that the latter would be a much smaller ship. This might well correspond to the 'patrol escort', in which case we're talking about a ship with six helicopters and a long-range SAM system; that sounds a lot like the Royal Navy's 'escort cruiser' of a few years later.

 

[Hood]

The PE seems to date from circa 1959, most probably linked with the appearance of the Golf-class which would be loitering within 400 miles of the coast. Also coincidental with the first-flight of the HSS-2 (SH-3 Sea King), so its likely the PE would be intended to operate HSS-1 (H-34/S-58) at the least and possibly HSS-2.

That neatly matches the Royal Navy's Escort Cruiser which began sketching up in early 1960 (for 8x Wessex/S-58) in terms of timing and similar concept.

 

[Yellow Palace]

US Aircraft Carriers once again has a bit more clarity, on both the PE and the PBG - which both came out of the Long-Range Objectives Group.

The PBG was intended in 1955 to replace the AGRs and DERs as a picket out of range of air attack, and wopld primarily be tasked with detection of submarines and bombers, with limited kill capability against submarines. There would be provision for interceptor control, and an ASW search and kill capability for those forming part of the inner contiguous line.

That lines up with The Navy in the 1970 Era, which called for 'about half' of a combined force of pickets and escorts to be equipped with guided missiles, and all to have either helicopters or ASW missiles.

The PE is identified as a 1959 proposal to support six helicopters for the 'cold-war trail' task, ultimately rejected because conventional ocean escorts were seen as more appropriate for wartime missions.

I suspect that there's a conceptual link here (it may just be that the helicopter-carrying escort was a pet project of someone on the committee!), and it would be fascinating to see the original reports for more detail.

 

[TomS]

US Aircraft Carriers once again has a bit more clarity, on both the PE and the PBG - which both came out of the Long-Range Objectives Group.

OK, I found the PE (p 352) but I'm not seeing the PGB mentioned. I'm sure I'm just missing it.

I do see the DHK, described as a 12,000-14,000-ton, 30-knot, ship with 12 helicopters and destroyer armament. But there were evidently a range of DHK configurations, because according to Friedman's "Notes on Sources" (p 422), one of them became the basis for SCS. These are probably the design studies listed as DH on p 353.

Edit: Also, what is The Navy in the 70s Era? That title doesn't turn up in searches.

 

[JFC Fuller]

Regarding the PGB, Friedman has a similar narrative in The Post War Naval Revolution, that appears to have a bit more detail, but requires some deciphering and may be garbled. The system details are my own addition, Friedman only gives the acronyms.

For the PGB, the suggestion is for a set of long range systems that would have required a very large ship with Terrier, an ASW missile and a sonar system called LORAD. LORAD was developed by the Navy Electronics Laboratory and would have been large, an active sonar intended to provide 100nm detection ranges in deep water using the convergence zone phenomena. For a 360 degree system there would have been 3 modules, each providing 120 degree coverage. A scaled-down trials system, with a single module and only enough processing for 30 degrees in bearing, was installed in AGSS-318 (more info here). The R&D effort fed into AN/SQS-26. Presumably, to support the air surveillance role, there would have been a sizeable radar suite too. Perhaps AN/SPS-43 combined with something like the, unsuccessful, AN/SPS-26 in addition to the required guidance sets for Terrier. On top of that the ship was meant to support 3-4 helicopters (my guess is HSS-1s). It was suggested that Victory ships could be converted at the cost of $20m each.

The CVHG would support 16 helicopters (again, guessing HSS-1s) and VTOL fighters (presumably Convoy fighters like the Lockheed XFV) and carry a 100nm missile, Friedman says this would be Talos but he puts it in brackets which I take to be speculation on his part. It would also carry a sonar, though this time Friedman calls it LOFAR which is a bit odd as thats a technique associated with low frequency passive detection (LO Frequency Analysis and Ranging), not a specific sonar system, it was the technique behind SOSUS and the Jezebel sonobuoy system. Perhaps the idea was to install a Jezebel signal analyser (something like AQA-3) in the ship and use the helicopters to drop sonobuoys? It's cost would be $40m and CVL conversions were considered.

The PBC was apparently a coastal radar picket, it wouldn't have Terrier but would be capable of long-range submarine detection and kill, Friedman describes it as the PGB without Terrier. Cost would be $15m.

All these ship types were to have a secondary convoy escort role.

In terms of numbers, in the Post War Naval Revolution, Friedman has
Distant Barrier: 50 ASW submarines
Ocean Picket Line: 35-40 surface ships (Friedman has PGB in brackets) stationed just outside the range of Soviet tactical air attack
Outer Offshore Pickets: 12 CVHG's in the Atlantic operating on the Newfoundland to Bermuda barrier, 12-15 PBCs in the pacific
Inner Offshore Pickets: 16-26 PBC or YAGR

This all feels like the product of a single study. There doesn't seem to be any SCB numbers for such vessels which implies it didn't go very far. It would have been wildly expensive to procure and operate such a system.

 

[TomS]

In US Naval Weapons, Friedman again (or possibly for the first time) mentions the PE, and notes that it was supposed to be a "broad-beamed" ocean escort carrying 6 HSS-1 helicopters. (p 129)

Edit: "Ocean escort" suggests that this was a slower ship, probably around 25-27 knots, like the DEs and DEGs, rather than the 30+ knots of the battle force escorts (DDs, DLGs, etc.). That's probably the main differentiator between the PE and the DHK, which was a 30-knot design.

 

[Hood]

Again, the RN Escort Cruiser shows what it might have been in terms of a ballpark outcome.
Study 6D in Jan 1960 - 5,400 tons, 459 x 55ft, 36,000hp steam for 26kt, 3,500nm at 20kt, 1x Mk 11 Tartar, 8x S-58 (all in a hull hangar)

The new DLG (Farragut) building from 1957 was 4,160 tons, 512 x 52ft 4in, 85,000hp steam for 32kt, 5,000nm at 20kt, 1x Mk 10 Terrier, 1x 5in, ASROC
The new DE (Bronstein) from 1961 was 2,360 tons, 372 x 41ft, 22,000hp steam for 26kt, 4,000nm at 15kt, 1x2 3in, ASROC and DASH [I've used this as a benchmark as the Claud Jones was very much an archetypical diesel-powered DE stemming from WW2 experience).

So I would agree with TomS, the result probably would be a ship more or less of DLG size (certainly 'broad-beam' compared with a DE) but with a smaller steam plant for 26-27kt and limited self-defensive armament - but presumably including ASROC - the nuclear depth-bomb option offering a certainty to destroy any loitering Golfs without relying on the temperamental Mk.43 torpedo from HSS-1).

 

[ptdockyard]

Glad to see I am not the only one that has to apply cryptology with Friedman's references. The designs briefly described but not illustrated in the Design History books are maddening.

 

[Yellow Palace]

OK, I found the PE (p 352) but I'm not seeing the PGB mentioned. I'm sure I'm just missing it.

It's on page 25, cunningly hidden in discussion of the role of the aircraft carrier. Which, since it wasn't an aircraft carrier, makes sense.

Edit: Also, what is The Navy in the 70s Era? That title doesn't turn up in searches.

That's a Januarly 1958 paper issued by the Chief of Naval Operations. It's referenced in US Aircraft Carriers, pp. 25-26, and was hosted in full by @RyanC at alternatewars.com. It's now on the Internet Archive here, I don't know if Ryan plans to re-host it on generalstaff.org in due course.

This all feels like the product of a single study. There doesn't seem to be any SCB numbers for such vessels which implies it didn't go very far. It would have been wildly expensive to procure and operate such a system.

That would be the snappily-titled Ad Hoc Committee to Study Long-Range Shipbuilding Plans and Programs, which published its report no earlier than December 1955. It seems that this committee evolved into the Long-Range Objectives Group.

The discussion in US Aircraft Carriers does imply a difference between the two types of barrier patrol ship, but identified both as PBG rather than separating out the PBC. The consistent use of VTOL fighters on aircraft carriers in deployments of 4-6 aircraft suggests that's what was envisaged for the CVHG as well.

Given that the same study envisaged something like 15 strike carriers, plus support and escort carriers (17 and 25 respectively according to Friedman, 24 and 39 according to Clare Scammell's 2001 PhD thesis), in addition to guided missile submarines a seaplane striking force, 'wildly expensive' seems to be an understatament!

As far as radars go, the contemporary LAMP LIGHT study recommended that radar picket ships should carry three air search radars: back-to-back 2D and 3D sets with antennae 45x25 feet, operating at 600 MHz and 1250 MHz respectively, and a height finding set with an antenna 10x20 feet operating at 5650 MHz. The report also discussed the need for a more seaworthy vessel than the YAGRs, noting that these were designed for inshore operations, and proposes the fitting of Denny-Brown-type stabilisers, or the use of unconventional hullforms.

Interestingly, the CVHG and PBC numbers give a total of 53 pickets in the two barriers. This corresponds very closely to the 52 pickets recommended by LAMP LIGHT for two coastal barriers, which does suggest the Ad Hoc Committee was aware of LAMP LIGHT.

Again, the RN Escort Cruiser shows what it might have been in terms of a ballpark outcome.
Study 6D in Jan 1960 - 5,400 tons, 459 x 55ft, 36,000hp steam for 26kt, 3,500nm at 20kt, 1x Mk 11 Tartar, 8x S-58 (all in a hull hangar)

The new DLG (Farragut) building from 1957 was 4,160 tons, 512 x 52ft 4in, 85,000hp steam for 32kt, 5,000nm at 20kt, 1x Mk 10 Terrier, 1x 5in, ASROC
The new DE (Bronstein) from 1961 was 2,360 tons, 372 x 41ft, 22,000hp steam for 26kt, 4,000nm at 15kt, 1x2 3in, ASROC and DASH [I've used this as a benchmark as the Claud Jones was very much an archetypical diesel-powered DE stemming from WW2 experience).

So I would agree with TomS, the result probably would be a ship more or less of DLG size (certainly 'broad-beam' compared with a DE) but with a smaller steam plant for 26-27kt and limited self-defensive armament - but presumably including ASROC - the nuclear depth-bomb option offering a certainty to destroy any loitering Golfs without relying on the temperamental Mk.43 torpedo from HSS-1).

It occurs to me that a further point of comparison for the PE might be the Japanese helicopter destroyers of the HARUNA and KURAMA classes. Somewhat later than the period in question, but a loosely similar concept of adding a significant helicopter force to a surface escort. In that case, you see:

DD (TAKATSUKI): 3,100 tons, 446 ft 2 in x 44 ft, 60,000 shp steam for 32 kt, 2 x 5in, ASROC, DASH
DDH (HARUNA): 4,950 tons, 502 ft x 57ft 5 in, 60,000 shp steam for 31 kt, 2 x 5in, ASROC, 3 SH-3

Looking at the timelines, the BRONSTEIN class is probably the right starting point for the PE - design work started in May 1958, and it was fairy welll defined by October that year. Shortly thereafter, opinion turned against the 24-knot escort, leading to the GARCIA and KNOX classes.

 

[apparition13]

"The Annapolis Riddle: Advocacy, Ship Design and the Canadian
Navy’s Force Structure Crisis, 1957-1965" by Richard Oliver Mayne talks about the development of the Iroquois class, but a lot of the discussion is focused on the DHH concept for an ASW destroyer carrying more SH3s. Their conclusion was since it took two birds to triangulate on a submarine, they would need 8 helicopters to maintain a 24 hour continuous search with two helicopters. However this sortie rate could only be sustained for around two weeks. If you wanted to maintain two helicopters in the air indefinitely you would need 15.

They investigated a number of configurations, some quite similar to those discussed here, others quite a bit larger, including buying Iwo Jimas to use as DHHs, building a purpose built ship of around that size, and ships carrying 8 SH3s, Mk13s and Mauler. All were part of pretty ambitious building programs, but cost concerns eventually resulted in the less ambitious DDH-280 Iroquois class.

In practical terms it means it would take four Spruance or OHPs or three Harunas to maintain two SHs in the air. The Harunas were meant to keep one SH3 airborne continuously, but given the Canadian conclusions it's unclear how long they could do that.

Hyuga and Garibaldi (in ASW form without Harriers), with a capacity for about 18 SH3/SH60 could maintain long term coverage or could keep two teams in the air for shorter time periods.

I find it interesting how Italy (Andrea Doria, Vittorio Veneto), France (Jeanne d'Arc) and the USSR (Moskva) all built cruiser sized ships of this type, but no one has returned to the concept.

 

[TomS]

It occurs to me that a further point of comparison for the PE might be the Japanese helicopter destroyers of the HARUNA and KURAMA classes. Somewhat later than the period in question, but a loosely similar concept of adding a significant helicopter force to a surface escort.

Conway's Navies in the Nuclear Age has a chapter on "Major Surface Combatants" by Eric Grove. It has the interesting note that Japan's 1969 Nakasone plan originally called for a pair of 8000-ton cruisers for Sea King and command support to two ASW flotillas. By 1972, this morphed into the two 5000-ton Haruna class DDH. I suspect Vittorio Veneto was the inspiration for the original JMSDF ships, likely with six Sea Kings rather than the three in the Harunas. A Japanese helicopter cruiser with the same fore end as the Harunas (ASROC and two 5-inch guns) would be interesting, but way under-defended. The JMSDF in this era struggled to fund enough AAW platforms due to the same foreign exchange issues that plagued lots of other navies. I'm pretty sure Terrier would have been out of reach, but perhaps Mk 13 with Tartar/Standard MR in lieu of at least one 5-inch gun?

 

[apparition13]

It occurs to me that a further point of comparison for the PE might be the Japanese helicopter destroyers of the HARUNA and KURAMA classes. Somewhat later than the period in question, but a loosely similar concept of adding a significant helicopter force to a surface escort.

Conway's Navies in the Nuclear Age has a chapter on "Major Surface Combatants" by Eric Grove. It has the interesting note that Japan's 1969 Nakasone plan originally called for a pair of 8000-ton cruisers for Sea King and command support to two ASW flotillas. By 1972, this morphed into the two 5000-ton Haruna class DDH. I suspect Vittorio Veneto was the inspiration for the original JMSDF ships, likely with six Sea Kings rather than the three in the Harunas. A Japanese helicopter cruiser with the same fore end as the Harunas (ASROC and two 5-inch guns) would be interesting, but way under-defended. The JMSDF in this era struggled to fund enough AAW platforms due to the same foreign exchange issues that plagued lots of other navies. I'm pretty sure Terrier would have been out of reach, but perhaps Mk 13 with Tartar/Standard MR in lieu of at least one 5-inch gun?

The front end of the Hatakaze class DDGs looks like the front end of the Haruna/Shirane* classes with the foreward five inch replaced by a Mk13. Hatakazes have a five inch aft where the DDHs have their hangar and flight deck, though the DDHs are longer and heavier.

On the note of defense, the DDH groups follow a 1/2/5 concept of 1 DDH defended by 2 AAW ships (DDG) and 5 general purpose destoyers (DD). This extends to the present with the Hyuga and Izumos defended by a pair of Aegis DDGs and five DDs, with each DD armed with Mk41s carrying ASROC and ESSM for local defense. The carriers operate the ASW air group, the DDGs provide long range air defense, and the DDs local air defense (ESSM), ASW (ASROC), and SUW.

*I've only seen Shirane and Kurama referred to as the Shirane class.

 

[TomS]

The front end of the Hatakaze class DDGs looks like the front end of the Haruna/Shirane* classes with the foreward five inch replaced by a Mk13. Hatakazes have a five inch aft where the DDHs have their hangar and flight deck, though the DDHs are longer and heavier.

On the note of defense, the DDH groups follow a 1/2/5 concept of 1 DDH defended by 2 AAW ships (DDG) and 5 general purpose destoyers (DD). This extends to the present with the Hyuga and Izumos defended by a pair of Aegis DDGs and five DDs, with each DD armed with Mk41s carrying ASROC and ESSM for local defense. The carriers operate the ASW air group, the DDGs provide long range air defense, and the DDs local air defense (ESSM), ASW (ASROC), and SUW.

*I've only seen Shirane and Kurama referred to as the Shirane class.

The closer contemporary would the the Tachikaze DDGs, which actually share Haruna machinery. (Edit: This is a minor nitpick. obviously. Same basic armament, just rearranged a bit to give the Hatakazes a helo pad.)

It would have been interesting to see whether this 1/2/5 concept could have held up if they had pursued the cruiser (CCH?) concept instead. The rather larger cruiser and extra helicopters would certainly cut into the funds available, but the extra helicopters might also have changed the calculus so they could adjust the 1/2/5 formula. Maybe 1/2/4 instead to free up money for bigger flotilla flagships and more helos?

 

[apparition13]

The closer contemporary would the the Tachikaze DDGs, which actually share Haruna machinery. (Edit: This is a minor nitpick. obviously. Same basic armament, just rearranged a bit to give the Hatakazes a helo pad.)

It would have been interesting to see whether this 1/2/5 concept could have held up if they had pursued the cruiser (CCH?) concept instead. The rather larger cruiser and extra helicopters would certainly cut into the funds available, but the extra helicopters might also have changed the calculus so they could adjust the 1/2/5 formula. Maybe 1/2/4 instead to free up money for bigger flotilla flagships and more helos?

I think since the Hatakazes post-date Shirane they are really just a cut down Shirane with Mk13 and no hangar, but we're picking nits.

I'm not sure when the 1/2/5 came into being, but the four original DDHs predate the full complement of 8 DDGs until the Kongos. They only had 6 Mk13 DDGs for 4 DDHs until the first 4 Aegis ships arrived.

The Hatakazes retired when the Mayas were commissioned, so there was some overlap with Hyuga/Izumo DDHs having Hatakaze escorts along with Kongos and Atagos for a couple of years before the Mayas.

I don't know if 1/2/5 makes as much sense for the PE designs for the USN, since they would be simultaneously further from their ports and the threat.

 

[Hood]

I'm guessing that in 1959 the effort needed to maintain a helicopter screen was probably under-estimated. At that time the USN (or any other navy) didn't have that much practical experience in such operations from ships (about 4-5 years at most). The USN obviously thought six HSS-1 would suffice, the RN went with 8. That's probably the upper limit for a non-flattop ship anyway.

I'll have to dig out the RN numbers on this for another comparison.

 

[TomS]

I'm guessing that in 1959 the effort needed to maintain a helicopter screen was probably under-estimated. At that time the USN (or any other navy) didn't have that much practical experience in such operations from ships (about 4-5 years at most). The USN obviously thought six HSS-1 would suffice, the RN went with 8. That's probably the upper limit for a non-flattop ship anyway.

I'll have to dig out the RN numbers on this for another comparison.

Almost certainly true. I think that's a big change from these 1950s era helicopter ships and the 1970s versions like SCS. SCS was bigger in large part to provide intermediate maintenance for it's one helos and those on the escorts.

In suspect that the PE was also seen as more of a picket or screen asset, rather than being the core of an ASW hunting task group.

 

[TomS]

I think since the Hatakazes post-date Shirane they are really just a cut down Shirane with Mk13 and no hangar, but we're picking nits.

Well, also with a switch to gas turbine propulsion.

On the Japan digression, I pulled out the 1972-73 Jane's Fighting Ships and I think it corrects one thing from Grove's account -- Haruna was ordered under the Third Five-Year Plan (1968-72 or 1967-71, depending on references), so it should actually predate the 8000-ton design.

And just for fun, Jane's talks about there being not one but two projected large destroyers: an 8000-ton helicopter design with 9 helicopters, reportedly inspired by Vittorio Veneto, AND an 8000-ton Command type ship with 4-6 helicopters. The latter was supposedly authorized in 1971, which implies it was fairly far advanced. But there are literally no other details.

Those might be variations of the same ship, discussed in different sources, I suspect. And whatever was authorized probably just got recast as the Shiranes.

 

[Tzoli]

Aren't you guys talking about the cancelled JMSDF Helicopter carrier design?

https://www.secretprojects.co.uk/threads/jmsdf-cvh-helicopter-carrier.23959/

 

[TomS]

Aren't you guys talking about the cancelled JMSDF Helicopter carrier design?

https://www.secretprojects.co.uk/threads/jmsdf-cvh-helicopter-carrier.23959/

No. These helicopter destroyers are later and carry many fewer aircraft.

Edit: The CVH proposals were late 1950s for service in the 1960s, and were for through-deck carrier designs with 18 or more aircraft. These helicopter destroyers/cruiser ideas are late 1960s to early 1970s. The Vittorio Veneto inspiration for at least one version implies a conventional surface combatants foredeck with a large hangar and flight deck aft.