The Royal Navy has installed its first next-generation Mk45 Mod 4A Medium Calibre Gun on HMS Glasgow, the lead ship of the Type 26 frigates.

HMS Glasgow is the first of eight City-class frigates designed primarily for anti-submarine warfare, but they are also equipped to perform a wide range of tasks, including mine-hunting, autonomous operations, and naval gunfire support.

The Mk45 Mod 4A gun replaces the Mk8 4.5in system, which has been in use since the 1970s. The Navy expects the Mk45 to be the Fleet’s mainstay for the next 50 years.

I was there recently with my drone, here are some images of the fit.

Main gun fitted on new British frigate

Neil Stevenson, Type 26 Weapons Group Leader at Defence Equipment and Support, stated, “This is a major milestone for the Type 26 MOD Weapons team and the Type 26 BAE Naval Ships Gunnery team. The Mk 45 Mod 4 is a proven, effective weapon that incorporates the latest technologies for today’s multi-mission warships.”

The Royal Navy added that the project has been supported by the US Department of Defense and the Royal Navy to ensure the weapon system is “at the forefront of gunnery technology and adaptability.”

The new gun, capable of firing shells up to 31.5kg at speeds of up to three times the speed of sound, is highly automated and safer for the crew. Unlike the older Mk8, the Mk45 Mod 4A features an automatic shell-handling system that pulls ammunition from a deep magazine to refill a 20-round ready-to-use stock.

This automation removes the need for sailors to manually load shells, reducing the risk of injury and improving operational efficiency.

Stevenson highlighted the cooperation between the Royal Navy, the US Department of Defense, and industry partners, stating, “This system is at the forefront of gunnery technology and adaptability, meeting the needs of the Royal Navy now and in the future.”

The installation of the gun took place at BAE Systems’ Scotstoun facility on the Clyde, with HMS Glasgow’s ship’s company in attendance.

Although the gun is currently without its barrel, it will be operational in due course and will contribute to the ship’s multi-role capabilities. According to the Royal Navy, the Mk45 Mod 4A will provide flexibility in engaging both surface and air threats, including drones and fast attack craft, and is interoperable with NATO allies’ systems.

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George has a degree in Cyber Security from Glasgow Caledonian University and has a keen interest in naval and cyber security matters and has appeared on national radio and television to discuss current events. George is on Twitter at @geoallison
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Shaun
Shaun (@guest_852132)
21 days ago

I am sure those on here with vastly more knowledge than I have in such matters can explain but I have never understood why they don’t standardise on the same 155mm calibre as the artillery?

Tess
Tess (@guest_852155)
21 days ago
Reply to  Shaun

Quite simply because it wasn’t deemed a requirement by the powers that be…and of course, money. Excerpt from NavWeaps.com: “During the early 2000s, the UK Ministry of Defense (MOD), DERA and RO Defence performed studies to assess future naval fire support requirements, particularly for the Type 45 destroyers then under development. Work was originally focused on developing a new 155 mm/52 “Future Naval Gun” which could take advantage of standard NATO 155 mm ammunition and the extended-range guided munitions already in development for land-based 155 mm artillery. However, MOD was unable to fund the high development cost associated with developing… Read more »

Last edited 21 days ago by Tess
ChariotRider
ChariotRider (@guest_852158)
21 days ago
Reply to  Shaun

Hi Shawn, Stockpiles would have a part in it. The USN is still big enough to require lots and lots of shells ready to fight an unexpected war. Unfortunately, blasting lots of shells off might be fun but they don’t all go bang so switching to a new gun means veeery carefully disposing of all those now obsolete shells… Then there is the tooling and development experience etc. right down the supply chain. Just lookup the 155″ gun debacle on the Zumwalt Class destroyers. The gun did not take NATO standard 155″ rounds and then they couldn’t get the overly… Read more »

Paul T
Paul T (@guest_852255)
20 days ago
Reply to  ChariotRider

AFAIK the 155mm Shells for the Zumwalt Destroyer debacle did work fine, but they just worked out to be way too expensive per round once the class of Ships got reduced from 30 to 3.

Supportive Bloke
Supportive Bloke (@guest_852163)
21 days ago
Reply to  Shaun

T45 was supposed to have 155mm to share stockpiles with army. There are photos of the test turret setup at Barrow.

Don’t think it ever did firing trials.

Got canned when T45 budget got stretched.

AlexS
AlexS (@guest_852171)
21 days ago
Reply to  Shaun

Weight, size, technology, history.

155mm rounds are 2 separate pieces,a round and a propellant bag.

Paul T
Paul T (@guest_852197)
21 days ago
Reply to  Shaun

Also the Germans trialled a 155mm Turret from the PZH2000 on one of their Frigates and found it to be unsatisfactory.

Davy H
Davy H (@guest_852273)
20 days ago
Reply to  Shaun

An interesting development is the RCH 155 selected for the British Army’s Mobile Fires Platform programme. If it can be fitted on a Boxer chassis, on which it can be fired whilst on the move, is there any reason why it can’t be fitted on a maritime platform?

Last edited 20 days ago by Davy H
AlexS
AlexS (@guest_852795)
19 days ago
Reply to  Davy H

It is not the same performance. Rate of fire is very low comparatively.
BAE 127 MK45 rpm 20
Leonardo(Oto) 127 rpm 32

RCH 155 rpm 9 and that is not continuous, and it will mean loosing the AA capability.

Last edited 19 days ago by AlexS
Supportive Bloke
Supportive Bloke (@guest_852162)
21 days ago

“ The new gun, capable of firing shells up to 31.5kg at speeds of up to three times the speed of sound, is highly automated and safer for the crew. Unlike the older Mk8, the Mk45 Mod 4A features an automatic shell-handling system that pulls ammunition from a deep magazine to refill a 20-round ready-to-use stock.”

Err there have been auto loaders on the 4.5” for a long time.

AlexS
AlexS (@guest_852170)
21 days ago

You sure it is the same thing they are talking about? autoloader is putting the round into the gun, not replenishing the autoloader.

DaveyB
DaveyB (@guest_852217)
20 days ago

BAe have an image of the new auto ammunition handling system. Which automates the whole process from the magazine to the turret autoloader. I don’t think the Arleigh Burke’s even have this?

Supportive Bloke
Supportive Bloke (@guest_852231)
20 days ago
Reply to  DaveyB

Mind you with RN automation mania it could be a thing.

DaveyB
DaveyB (@guest_852233)
20 days ago
SailorBoy
SailorBoy (@guest_852243)
20 days ago

He’s right, the T26s are going to have ammo handling for the 5″ completely automated.
Similar to the munitions handling on the QEs, it will probably save quite a few crew.

Supportive Bloke
Supportive Bloke (@guest_852247)
20 days ago
Reply to  SailorBoy

I agree it will save a few crew.

Trouble is that it probably won’t save the numbers from the trades we are short of.

Dern
Dern (@guest_852326)
20 days ago

Auto loaders have been, but pulling out of the deep magazine I think was still done by hand for the 4.5.

Gunbuster
Gunbuster (@guest_852349)
20 days ago

Mk 8 In the gun bay you still lift and shift by hand to feed the turret feed ring via the auto loader The rounds in the magazine are lifted and shifted by hand to the hoist that takes them up to the gun bay. From the gun bay hoist you lift and shift to the gun auto loader. It is hard work especially in a sea way and the gun bay ready use racks require you to reach 6 ft up to pull shells out of the top row of storage tanks. As each shell is a complete one… Read more »

Supportive Bloke
Supportive Bloke (@guest_852380)
20 days ago
Reply to  Gunbuster

I was only ever involved in loading its twin turret predecessor…that was seriously hard work…

For some reason I’d thought the Mk8 had been fully automated when it was moved from hydraulic to servo.

Gunbuster
Gunbuster (@guest_852701)
19 days ago

I was on the last maintainers course for the Mk6 back in 1986. So I can relate to how hard the Mk 6 was. Although by then the valve powered servo system in the turret had moved on to …transistors and solid state! No more pulling V5 the course /fine changover control to make it stay in Course control ( FOST funny that was.) Mk8 Mod 1 pulled most (but not all) of the hydraulics out of the turret. The biggest aid to reliability improvements was changing the Honeywell microswitches for magnetic reed switches. The new control system for the… Read more »

Supportive Bloke
Supportive Bloke (@guest_852711)
19 days ago
Reply to  Gunbuster

The microswitches were a nightmare as we have both observed before, the rubber boots that covered them perished allowing the insides to get damp/seawater on them with the inevitable corrosion – not usually to the plated contacts but to the terminals where the wire was clamped in.

With the result the turret loom got shorter and shorter as you had to trim back to sound uncorroded wire.

Gunbuster
Gunbuster (@guest_852747)
19 days ago

Yep. Same things were used on Sea Dart launchers and handling system and Corvus 3 Inch launchers…and they also where renowned for their excellent reliability! 🙄

Last edited 19 days ago by Gunbuster
Matt
Matt (@guest_852299)
20 days ago

Good gun… but it does seem to be on the wrong ship. T31 seems much more likely to end up on the gunline, and is equipped with a peashooter…

Supportive Bloke
Supportive Bloke (@guest_852712)
19 days ago
Reply to  Matt

Depends what you want it for.

If you want to patrol the gulf it is also pretty well specified.

If you want it to throw an umbrella over RFA to prevent a rerun of bomb ally then a T31 is perfect for the job.

Neil Brentnall
Neil Brentnall (@guest_852458)
20 days ago

It’s great to see the Royal Navy getting new ships with up to date weaponry and systems!! We need more ships of all sorts and sizes to stave off the threat from Russia, China, Nth Korea, Iran to name a few!!
The Government should be increasing the MOD’s budget for ships, submarines, plus motorised heavy, including tanks, more infantry, more men/women, not less!!