Mark 71 MCLWGS enters service

[Colonial-Marine]

Lets say things turn out a bit differently with one of the US Navy's big missed opportunities of the 1970s. Instead of being cancelled most Spruance class destroyers enter service with a Mark 71 8"/60 caliber gun at the fore and a Mark 45 5"/54 at the stern. Maybe with some luck the CGN-42 class doesn't get cancelled too and those also have a Mark 71 up front. Along with the reactivated and modernized Iowa class battleships the USN has no shortage of naval gunfire support for the time being.

What changes down the line though? Is it decided to include a Mark 71 on the eventual Arleigh Burke class? Is the design lengthened to also have a Mark 45 aft like on previous destroyers and cruisers? Does the US Navy still pursue the 155mm AGS for DD(X) or is there no longer the requirement for such a gun system? Do any of the Spruances stay in service longer?

 

[CV12Hornet]

The CGN-42s aren't getting built. Too expensive. They're also not showing up on the Burkes, the mount was too tall.

There's a pretty good chance that the Mark 71 means no AGS. A new-design 240-lb projectile was planned that would have likely been able to match the AGS' planned conventional ballistic projectile, and the 66-km extended-range shell tested on St. Paul could have been ported over. From there longer-ranged projectiles can be developed.

Whether this can save the Zumwalt program is an open question. On the one hand, the class' cancellation was largely down to their mission evaporating, which this doesn't change. On the other hand, it's one less advanced technology to develop, which can only help with the costs and development delays.

It definitely doesn't mean the Spruances staying on longer, especially if, as I suspect, the US Navy intends to reuse the 8" guns from them on the Zumwalts.

 

[uk 75]

https://www.secretprojects.co.uk/threads/mk-71-lightweight-8-gun.1077/#post-81428

Lots of relevant stuff here.
Basically the fire support role was sorted up until 1991 by the four Iowas so the Mk71 was not needed

 

[Cordy]

https://www.secretprojects.co.uk/threads/mk-71-lightweight-8-gun.1077/#post-81428

Lots of relevant stuff here.
Basically the fire support role was sorted up until 1991 by the four Iowas so the Mk71 was not needed

The Iowas long gone, were due due to be replaced by the Zumwalts AGS155/LRLAP cancelled 2016, so USN left with no equivalent the fire support role mission, has the Tomahawks at $1 million pus each and would be very expensive if required to launch in the thousands that maybe required, the reason given when AGS155 LRLAP projectile was cancelled was due to its estimated cost of $$800,000 to a $1,000,000 each.

 

[Archibald]

Did Gerald Bull helped extending that gun range ?

 

[uk 75]

https://www.secretprojects.co.uk/threads/mk-71-lightweight-8-gun.1077/#post-81428

Lots of relevant stuff here.
Basically the fire support role was sorted up until 1991 by the four Iowas so the Mk71 was not needed

The Iowas long gone, were due due to be replaced by the Zumwalts AGS155/LRLAP cancelled 2016, so USN left with no equivalent the fire support role mission, has the Tomahawks at $1 million pus each and would be very expensive if required to launch in the thousands that maybe required, the reason given when AGS155 LRLAP projectile was cancelled was due to its estimated cost of $$800,000 to a $1,000,000 each.

"up until 1991" is that not clear. I was referring to the Mk71 not Zumwalt.

 

[Colonial-Marine]

The CGN-42s aren't getting built. Too expensive. They're also not showing up on the Burkes, the mount was too tall.

There's a pretty good chance that the Mark 71 means no AGS. A new-design 240-lb projectile was planned that would have likely been able to match the AGS' planned conventional ballistic projectile, and the 66-km extended-range shell tested on St. Paul could have been ported over. From there longer-ranged projectiles can be developed.

Whether this can save the Zumwalt program is an open question. On the one hand, the class' cancellation was largely down to their mission evaporating, which this doesn't change. On the other hand, it's one less advanced technology to develop, which can only help with the costs and development delays.

It definitely doesn't mean the Spruances staying on longer, especially if, as I suspect, the US Navy intends to reuse the 8" guns from them on the Zumwalts.

Shame about the CGN-42, even without the poor economy and politics of the '70s would they have likely met the same fate? It seems like most of the nuclear powered cruisers while expensive had a lot going for them and certainly had more room for growth than the Ticonderogas. The Burke as designed couldn't take the Mark 71 but if it had entered service on the Spruances and maybe others would the class have been designed to incorporate it?

 

[CV12Hornet]

Shame about the CGN-42, even without the poor economy and politics of the '70s would they have likely met the same fate? It seems like most of the nuclear powered cruisers while expensive had a lot going for them and certainly had more room for growth than the Ticonderogas. The Burke as designed couldn't take the Mark 71 but if it had entered service on the Spruances and maybe others would the class have been designed to incorporate it?

Yes. Nuclear is a major expense and as the CGBL studies showed it's significantly more economical to go with a larger conventionally-powered hull if you simply want more growth room over the Ticonderogas.

I doubt it. You'd need to do a very significant redesign of the bridge structure and the bow to make an economical fit - one disadvantage I didn't mention was that there would be space for only 204 8" rounds in a straight DDG-51 modification, as opposed to the 475 planned for the Sprucans. For a ship that was intended to be a cheaper alternative to the Ticonderogas this is likely more trouble than the gun is worth.

 

[apparition13]

The modular Burke design shown here:

shows that a Mk-71 could fit in a 64 cell Mk41 space.

I suspect that, had it been deployed, guided (and potentially ramjet) shells would have been developed for NGFS, SUW, and perhaps even AAW.

 

[Firefinder]

Odds are that if the MK71 been deployed on the Spruances or the Conventional Power Strike Cruiser design in...

Say the early 80s when the Burkes was being design.

They would have made the hull able to take the gun from the Get Go. As in they design it from day one with the expectaction that they may put the MK71 on the later Burkes or even order them with the gun.

But since the MK71 program basically died in 1978, 2 year before navy even issue out the requirements of what became the Burke Program in 1980 in real life...

Bath didnt bother designing it in outside of the bare mimnum when someone ask if it was possible, cause you dont waste money designing in the ability for using dead programs.

 

[robunos]

What are these ?




cheers,
robin.

 

[apparition13]

Type A vstol, probably ASW variant. If I had to guess, Grumman G-698.

https://www.secretprojects.co.uk/threads/grumman-g-698-v-stol-us-navy-type-a-proposal.1200/#post-74622

Another lost opportunity. Personally I would have liked to have seen two of the Type A proposals developed, the tandem fan Vought 530 as the risky option with the GD/Canadair CL-84 as the safe.

 

[Colonial-Marine]

That is an interesting diagram of the Burke class I hadn't seen before. What did they ultimately use that space for between the rear 64 cell VLS and the helipad before they put the hanger there on the Flight IIA?

 

[robunos]

Type A vstol, probably ASW variant. If I had to guess, Grumman G-698.

Looks like the G-698-420 variant, see HERE.


cheers,
Robin.

 

[TomS]

They would have made the hull able to take the gun from the Get Go. As in they design it from day one with the expectaction that they may put the MK71 on the later Burkes or even order them with the gun.

Looking at the design evolution of the DDG-51, I honestly doubt it.

Remember, the early passes at the ship that evolved into the Burke started with no guns except Phalanx. They soon acquired a 76mm gun and later in the process switched to the 5-inch gun. And even then, the gun was aft, where there would not have been enough hull depth for the Mk71 (just as there was not enough depth aft on the Spruances). It was only very near the end of the design evolution that the gun was moved forward, mainly for aesthetic reasons I suspect.

You'd have seen Mk71 in the DD-963 refits (possibly at the expense of sone of the VLS cells). If the NSFS role had actually been popular, perhaps a couple of late DDs could have been ordered as dedicated fire support ships with a second gun and rearranged Sea Sparrow/helicopter facilities.

 

[isayyo2]

Had the Mk 71 overcome its political and technical hurdles entering service in say 1977, would the altered DDGY/DDGX programs even be similar to what we know the DDG-51 turned into? Best case scenario, there would be 31 Spruance's roaming the seas with 8" guns by the early 80s and a hot production line production the Spruance's CG-47 cousins. Rather than develop a whole new DDG class, could a "Flight II" Spruance suffice? Perhaps a 61/64 VLS cell aft, 12 or 24 self-defense cells for Sparrows forward, the all important Mk 71 gun, and an early NTU SPS-48 fire control system launching in the mid 80s. The last Spruance, USS Hayler, saw some interesting mods from the Tico production.

former Hayler MPA/NAV • 8 years ago
HAYLER DD-997 was unique among the DD-963 class, including:
- built with SPS-49 air search radar vice SPS-40
- about 900 tons full load greater displacement due to Kevlar armor installed during construction
- greater F-76 capacity than DD-963 class
- DDG-993 class potable water storage capacity (increased capacity)
- CG-47 distillation units (increased fresh water production capacity)
- CG-47 sized a/c units (increased chill water capacity)
- DD 963 capacity generators, but DDG-993 electrical distribution system
- CG 47 class waste heat boilers
- DDG-993 class fire pumps
- DD 997 unique CRP components
The ride and space of a Spruance with benefits of improved Tico aux systems. It was a great ship, decommissioned way too soon.

Not sure if the Iowa's were still feasible in a Mk 71 world, but the possibility is always there.

 

[CV12Hornet]

Had the Mk 71 overcome its political and technical hurdles entering service in say 1977, would the altered DDGY/DDGX programs even be similar to what we know the DDG-51 turned into? Best case scenario, there would be 31 Spruance's roaming the seas with 8" guns by the early 80s and a hot production line production the Spruance's CG-47 cousins. Rather than develop a whole new DDG class, could a "Flight II" Spruance suffice? Perhaps a 61/64 VLS cell aft, 12 or 24 self-defense cells for Sparrows forward, the all important Mk 71 gun, and an early NTU SPS-48 fire control system launching in the mid 80s. The last Spruance, USS Hayler, saw some interesting mods from the Tico production.

former Hayler MPA/NAV • 8 years ago
HAYLER DD-997 was unique among the DD-963 class, including:
- built with SPS-49 air search radar vice SPS-40
- about 900 tons full load greater displacement due to Kevlar armor installed during construction
- greater F-76 capacity than DD-963 class
- DDG-993 class potable water storage capacity (increased capacity)
- CG-47 distillation units (increased fresh water production capacity)
- CG-47 sized a/c units (increased chill water capacity)
- DD 963 capacity generators, but DDG-993 electrical distribution system
- CG 47 class waste heat boilers
- DDG-993 class fire pumps
- DD 997 unique CRP components
The ride and space of a Spruance with benefits of improved Tico aux systems. It was a great ship, decommissioned way too soon.

Not sure if the Iowa's were still feasible in a Mk 71 world, but the possibility is always there.

A "Flight II" Spruance doesn't fit the US Navy's needs heading into the Burke class, which is not more land attack or ASW firepower, but a medium-cost AEGIS escort to replace the old steam-powered Terrier/Tartar escorts - the Adams, Farragut, Leahy, and Belknap classes, plus the old Terrier-armed nuclear cruisers, all of which are going to hit the end of their lifespans from 1995-2002 and which the largely unmodernized Farragut and Adams classes aren't going to hit anyway.

 

[isayyo2]

A "Flight II" Spruance doesn't fit the US Navy's needs heading into the Burke class, which is not more land attack or ASW firepower, but a medium-cost AEGIS escort to replace the old steam-powered Terrier/Tartar escorts - the Adams, Farragut, Leahy, and Belknap classes, plus the old Terrier-armed nuclear cruisers, all of which are going to hit the end of their lifespans from 1995-2002 and which the largely unmodernized Farragut and Adams classes aren't going to hit anyway.

All very true. Perhaps with hindsight, knowing that DDG-51 would evolve into something much larger and RIM-156 not entering service until 99 would it have been cheaper/beneficial to continue building AEGIS CG's and NTU DDGs on Spruance hulls and achieve cost savings with their commonality?

 

[CV12Hornet]

All very true. Perhaps with hindsight, knowing that DDG-51 would evolve into something much larger and RIM-156 not entering service until 99 would it have been cheaper/beneficial to continue building AEGIS CG's and NTU DDGs on Spruance hulls and achieve cost savings with their commonality?

More Ticonderogas? No. Hell no. For one, the Burkes are genuinely cheaper - a Ticonderoga early in the production run cost about $600 million more per ship in 2010 dollars compared to a Burke similarly early in the production run. For another, the Ticonderogas had significant construction issues as a result of cramming AEGIS and either two full Mark 26 magazines or two 64-cell VLS grids into the Spruance hull. They suffer from topweight and stability issues, superstructure cracks, are low in the bow, and suffer some from seakeeping issues.

On the other hand, more NTU DDGs (presumably Kidds) are simply not as capable, both on the AAW end and on the fact that they're built on a Spruance hull.

Personally, I think any savings on hull commonality are overblown, given the real money is in the combat systems. You're much better off standardizing on the weapons and electronics as much as possible.