Babcock International has reached a milestone in its five year contract with the Ministry of Defence’s International Guns, Missiles and Rockets (IGMR) project team.

The company says that its aim is to ‘deliver a rejuvenated 4.5” Mk8 Mod 1 Medium Calibre Gun programme’ for the UK’s Royal Navy.

Over the course of the contract, which will implement general performance improvements and address equipment obsolescence, Babcock will drive an increase in reliability and availability of weapons systems. Benefitting from significant investment, the Mk8 equipment is planned for utilisation across numerous Royal Navy platforms with the potential for deployment on future MoD contracts say the firm.

Highlighting a significant milestone for the programme, Babcock – working in collaboration with BAE Systems – has delivered a number of design interventions ahead of successfully completing a series of live firing trials with QinetiQ at MoD’s Eskmeals Range in Cumbria.

These trials mark the first land based firing of a fully turreted 4.5” gun since the closure of HMS Cambridge in 2001.

Conducted over a five-day period and utilising multiple land and sea sites, various range, accuracy and altitudes were successfully tested. Results will now be applied to the programme as the contract progresses say the company.

Martin Laity, Director of Mission Systems at Babcock said:

“The team realised a key milestone with the live firing trials. Establishing and delivering on a suite of well-defined KPIs will ensure the programme is set up for success as the Mk8 contract progresses towards an effective, reliable and cost-effective solution for the Ministry of Defence.”

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Mike R

All ready for installation in our Type 31e’s then as the Type 23’s are decommisioned?

Glass Half Full

That would seem to be the implication of the comment “with the potential for deployment on future MoD contracts” although the original T31e RFI had a requirement “1 x Medium Calibre Gun ≥ 57mm and interoperable munitions with Allies.” but its hard to see the MK8 being interoperable with anyone we’d normally expect as allies. That said total cost of ownership of a refurbished 4.5″ might work out less expensive than anything new at ≥ 57mm so helping to achieve the £250M target. We may also have adequate stockpiles of ammunition sufficient for any anticipated requirements without needing to make… Read more »


The requirement doc for the T31e class shows the minimum gun calibre allowed in 3″, that means nothing less than a 76mm which rather excludes the Bofors 57mm.

Glass half Full

I cut and pasted “1 x Medium Calibre Gun ≥ 57mm and interoperable munitions with Allies.” straight from the T31e RFI Appendix F. Is there a more recent specification?


Very interesting, the initial program launch document stated: “Medium range gun >76mm capable of Naval Gun fire Support.”

The document above was prior to the RFI so clearly they realised that there is not enough difference between the 57mm or 76mm to make leaving out the former worth it. It allows for a more sensible flexible program.

Useful info thanks.

Mark L

The Mk8 gun needs people in the gunbay and magazine to move ammunition by hand. It would be a problem on Type 31e as the RN want a small crew.
However, refurbished Mk8 might be cheaper than any alternative – depending on how the MoD prices it as GFE.

Steve Taylor

You would only have 2 to do that. It isn’t as labour intensive as my favourite the Mk 6. All mounts should have two guns because awesome.

Harry Bulpit

why are we investing more money in to this weapon system? especially since where moving to the 5 inch for the Type 26 and looking at a smaller gun for the Type 31.


Type 23s will be in service into the 2030s and there has been no indication that the Type 45s will be upgraded to the 5 inch.


There are also CGI mock ups of the Leander with the 4.5 inch installed so I don’t think this platform will be retired anytime soon.

Harry Bulpit

interesting to hear how long the type 23 is expected to continue. thanks for the response.


Mid 2030’s. St Albans was commissioned in 2002 and the fleet are being kept in service for over 30 years.

Steve Taylor

Darings will never go on the gun line. Better Mk8 get replaced with a nice 76mm instead or even one of the heavier CIWS systems.

Rob N

The gun space could be ussed for extra SAMs – not a bad idea. However, i would like to see all T45s with a SSM to protect themselves from other ships.


Excellent question Harry, why invest in an obsolete system?


So that it is no longer obsolete.
It would be a lot more expensive to rip them out and replace with them with foreign design that offers little additional benefit.


Shoot 5 times as far with precision – no big deal I guess.


4.5 Mk8 is old yes but so is the Mk 45. It first came into service in its original configuration in the early 70s as did the original 76mm Oto. MK 8 with base bleed rounds has good range and is phenomenally accurate in the NGS and surface role. Its more reliable in the Mod 1 configuration than the original with most of the hydraulics now replaced by electrics. (That was a great day for Gunbusters…less oil leaks and better reliability) Some of those electrics are going to be obsolete though. Limit switches, reed switches, circuit boards, connection plugs etc…they… Read more »

Steve Taylor

……hydraulics now replaced by electrics.

We all know the true purpose of the Mk8 Mod 0 was to give the weapon engineering team something to do. 🙂


On the old Mk6 the oil leaks stopped the deck going rusty!

Steve Taylor

HMS Cambridge closed in 2001. Blinking ‘eck time flies.


Yes it does…many a happy time spent doing CRW shoots at the Rock or towed sleeve targets and 4.5s out to sea.


I’ve just driven past HMS Dragon in port in the Middle East and can confirm that she has a mk8 gun on the forecastle.


Show off! 🙂


I’ve just driven past Gary’s Car Sales and can confirm he has a Mk 3 Escort on the forecourt.

Different loves I guess 🙂


…Lives, not loves.


Jeeves kindly slowed the Rolls so I could take a photograph out of the window.

But on a serious note, seeing this type of defence engagement in action is quite something and has a disproportionate effect on raising the UKs standing in comparison to its cost. Makes me even more convinced that the forward-basing decision of a type 23 is the right one.

Gavin Gordon

I’d anticipate that the Type 45s will keep the Mk8 regardless in oeder to maximise the conversion potential for additional silos.

Steve Taylor

How does retaining Mk8 maximise conversion potential for additional silos?


It’s cheaper therefore saves money to potentially pay for mk41s

Steve Taylor

I see. But the money spent on Mk 8 was spent yonks ago. I would say it would have negligible impact on spending on Mk41 today. Now not spending on replacing might save a groat or two. Though if I were in charge I would install a nice 76mm or a 35mm or over CIWS. But it doesn’t need a medium gun really. *** I doubt Darings will ever see Mk41. They are a one trick pony and for that role Sylver (I can never remember how to spell that…..) is already enough I suppose. Depends on what the RN… Read more »

Chris T

I thought stocks / manufacturing of 4.5 was a key an issue in the move to 5”?


I thought the RN was moving to the US 5″ gun as standard. I like the 76mm oto for it’s rapid fire AA/anti-missile capabilities further out than Phalanx can reach, but for surface work & shore bombardment heavier caliber is better for both range & damage.

Steve Taylor

With only 6 of them Daring will never ever go on the gun line. When the balloon goes up they will be sitting with the task group.

Gavin Gordon

Mk45 installation would evidently impinge too far into the space left for mk41 silos immediately to the rear of forward gun, Steve.


Any news when the Type 45s will be getting those extra Type 41 VLS? I’d assumed when the RN reduced the number from 16 to 12 it was to allow the extra space for the larger 5” gun…


Errr…From the last time I was on a T45 there is no space aft of the gun for a silo. The silo space allocated for Mk41/ gym is abaft the Aster silo, where the current Harpoon, when fitted is, bolted on

Gavin Gordon

In extremis?

Mr Bell

It isn’t the end of the world for the RN to upgrade these guns and fit them onto the type 31s. I think having 2 calibres of gun. 5 inch for type 26 and 4.5 inch for everything else is fine. Plenty of other navies have more than 1 medium calibre gun
If it brings unit price down and allows type 31 to have more VL missile silos or better sensors for the unit price then that is fine.


I really would like to see the Otto 76mm put on the T31’s, I really do think the uk is missing a trick here, we have a great hull form in the T23, we have designers like spartan systems who could reinvigorate the layout of that base hull form and we could create a really good ASW platform on the cheap (as we have the hull design already). The size of the current T23 is virtually identical to that required for T31. So we have everything we need in reality. No need for a stretched Kareef or an huitfeldt class… Read more »

Steve Taylor

Your T26’s would be deep field using 2087 to provide an ‘area) (sub)surface picture. (This is where long range SeaCeptor as it will push the air defence bubble even further out.) Where the RN will struggle is closer into the centre of the group because of a lack T26 and Merlin in numbers. This is where stripping out T45’s ASW capability is going to hurt; never mind the cock-up they made with its noise signature which should be good for an IEP hull even without special considerations. How good T31 will be on this front I don’t know. You can… Read more »


I have worked and maintained Oto 76s. Yes its a good gun but there are issues when compared to a 4.5. The feed system on an oto is mechanically linked together, along with electrical position switches, from the feed ring through the spiral hoist, through the loading arms up to the gun and ejection chutes. To keep weight down most of the structure is alloys and has holes through it to reduce weight at the expense of overall structural strength and robustness. When something mechanical fails and believe me it does occasionally, the amount of bent metal, broken parts and… Read more »


Forgive someone not in the know: Why do we not just use the basic hull of the T26 for the T31E? Remove all the fancy ASW stuff, just keep the steel. UK (or a UK company at least) own the design, it’s already been approved etc. My understanding is that steel is (comparatively) cheap and systems are expensive. So why are we not putting specialist and GP applications on the same hull? Is the T26 so much bigger that it won’t fit with the lean crewing requirements of the T31? I appreciate that we’re hoping to go with a different… Read more »

David Steeper

Hope most of you right about 31’s getting the 4.5. Along with the new 5’s it gives them shore bombardment, anti – ship and anti – air capability. Add in a helicopter hanger and we’ve got a warship.


Anti Air was removed from the 4.5 years ago.
No Target Triggered Burst (TTB’s) anymore.

David Steeper

Why would they do something so stupid ? Oh right daft question !


Does this make any difference to the use of advanced munitions?