Martin Baker Tankbuster

[blackkite]

Hi! Martin Baker Tankbuster.

https://nofineline.com/martin-baker-anti-tank-172/
"The Martin Baker Tankbuster was a paper design conceived by James Martin, co-founder of the Martin-Baker Aircraft Co. Ltd., famous for the manufacture of ejection seats. The very compact airframe and wingspan, combined with heavy armour (5,000lbs of ½ inch armour plate) and offensive weaponry, could have made the MB Tankbuster a formidable close support aircraft. Built around the primary British 57 mm anti-tank gun of World War 2 (Ordinance QF-6 6 pounder), the aircraft was to have been powered by a rear mounted the Rolls-Royce Griffon engine."

Model. What is this nose gun?
https://modelingmadness.com/review/viet/gb/burstmbt.htm

Six pounder anti tank gun(Ordinance QF-6) 6 pounder is this?
https://www.canadiansoldiers.com/weapons/ordnance/6pounder.htm

 

[Schneiderman]

Patent GB556826 JUne 1942

 

[DWG]

Technically that should be the Ordnance QF 6 pdr 7 cwt. Ordnance = artillery, Ordinance =laws, but you'll probably find the mistake more often than not. The 7 cwt is important as there were also 6, 8 and 10 hundredweight 6 pdrs, which were completely different weapons. The autoloader is probably the same Molins one used on the powered naval mount and the Tsetse Mosquito XVIII. Details here http://www.quarryhs.co.uk/Molins.htm

The fuselage of the Tankbuster has always struck me as extremely narrow for fitting the Molins. Even with the 50 calibre barrel, that's only 2.85m breech to muzzle, and there's about a metre of barrel ahead of the nose. It likely puts the autoloader and breech assembly roughly over the forward gear leg, which is probably good for weight distribution on the ground, but likely needs some hefty structural members in the fuselage at that point, further restricting available space. For C-of-G purposes the aft mounted Griffon needs to balance both the gun and autoloader, and all of the nose mounted armour. You've got a fuselage with all the weight at the extremes, and that is going to be structurally interesting.

Disregard the gun on the model, the modeller says it's an ahistorical borrowing to replace the proper barrel.

 

[Schneiderman]

From the patent

 

[DWG]

Thanks, that doesn't appear entirely consistent with the Molins which has a feedtray to the side of the breech, whereas the patent illustration seems more like it surrounds the breech. ISTR some of the 40mm S Type feeds may have been similar. Possibly Martin intended scaling up an S Type feed, though it would be entirely consistent of him to get distracted into designing a new feed of his own.

 

[Schneiderman]

James Martin was notorious for redesigning mechanisms, including gun mounts annd feeds, usually with some success. No doubt he had some compact loader in mind for this aircraft but I have looked through his other patents but cannot find anything of that type.

EDIT....actually I just read through the patent and surprisingly Martin says this.....

 

[CJGibson]

On the patent drawing, what is the arc whose radius is labeled '27'?

Chris

 

[Schneiderman]

Not smart for an aircraft designed to fly at low level

 

[DWG]

Schneiderman: hand-loaded? Ouch! One shot per pass doesn't seem to go with the number of rounds carried, and having looked at video of 6 pdr firings the recoiled position doesn't seem consistent with the pilot position (and would require a mechanism to latch it in the recoiled position).

Chris: escape hatch I would presume. Several other WWII era pusher concepts used that as a mechanism to ensure the pilot cleared the propeller disc.

 

[Schneiderman]

Schneiderman: hand-loaded? Ouch! One shot per pass doesn't seem to go with the number of rounds carried, and having looked at video of 6 pdr firings the recoiled position doesn't seem consistent with the pilot position (and would require a mechanism to latch it in the recoiled position).

You've disillusioned me now, I thought it was a great idea

 

[CJGibson]

Thought so, but you never know...

Chris

 

[blackkite]

From the patent

Wow Thanks a lot. Excellent contribution!! This is what I want to see.
Radiator cooling air intake is very large.

 

[blackkite]

Technically that should be the Ordnance QF 6 pdr 7 cwt. Ordnance = artillery, Ordinance =laws, but you'll probably find the mistake more often than not. The 7 cwt is important as there were also 6, 8 and 10 hundredweight 6 pdrs, which were completely different weapons. The autoloader is probably the same Molins one used on the powered naval mount and the Tsetse Mosquito XVIII. Details here http://www.quarryhs.co.uk/Molins.htm

The fuselage of the Tankbuster has always struck me as extremely narrow for fitting the Molins. Even with the 50 calibre barrel, that's only 2.85m breech to muzzle, and there's about a metre of barrel ahead of the nose. It likely puts the autoloader and breech assembly roughly over the forward gear leg, which is probably good for weight distribution on the ground, but likely needs some hefty structural members in the fuselage at that point, further restricting available space. For C-of-G purposes the aft mounted Griffon needs to balance both the gun and autoloader, and all of the nose mounted armour. You've got a fuselage with all the weight at the extremes, and that is going to be structurally interesting.

Disregard the gun on the model, the modeller says it's an ahistorical borrowing to replace the proper barrel.

Thanks you very much for your kind and excellent lecture.
Anyway, let's keep on going.

 

[CJGibson]

Looking at the drawing the magazine/autoloader appears to be cylindrical. Could it be similar to the design used in Green Mace or Skysweeper?

Chris

 

[Schneiderman]

Chris, see #5. Martin intended the gun to be loaded manually, the breech sitting between the pilot's legs. Ouch!

 

[CJGibson]

Flying, loading, aiming, firing while taking evasive action to avoid being hit by copious flak. Sounds similar to this:


Chris

 

[Schneiderman]

And with the gun just feet away from him within the same enclosed space his eardrums are going to suffer

 

[Sherman Tank]

Explains why it stayed a paper study, doesn't it?

 

[Foo Fighter]

Considering the problems with decision making at Martin Baker it is not a surprise, how many projects did they get totally off the ground anyway? I am talking about finishing a project rather than refining the thing to death.

 

[blackkite]

Bristish air staff thought that Hurricane Mk.Ⅳ would meet the need.
(From Tony-san's great book. )

 

[cluttonfred]

Old thread, new question.... Has anyone ever seen any drawings of the numberless M.B. Tankbuster design in any of the alternative configurations without the single big gun? Optional arrangements were suggested at the time in various combinations of 47mm (3-pounder)/40mm/20mm cannon, rockets, and bombs, but I have never seen any artwork depicting those options. I am curious because the integral armor protection of the M.B. design could have been very useful...Hurricane Mk IV tankbusters suffered a very high attrition rate from ground fire. Cheers, Matthew

 

[CJGibson]

Matthew, Didn't see any alternative armament for the Tank Buster while I was digging around the Low Attack Aircraft for Typhoon to Typhoon. These designs were to be armed with 3-4 x 40mm cannon plus bombs and rockets. Much of the correspondence on the Tank Buster involved the DCAS advising Martin to drop it and get on with his fighter.

There was a rather intriguing Burnelli design mentioned, but neither I nor Schneiderman could find anything definitive about it. It had a ventral cockpit apparently!

Chris

 

[DWG]

There was a rather intriguing Burnelli design mentioned... It had a ventral cockpit apparently!

Clearly he wanted nothing to do with that "Beware the Hun in the Sun" nonsense!

 

[cluttonfred]

Thanks, Chris. I do remember reading that Martin was discouraged from pursuing the tankbuster concept, so it's quite possible that no drawings exist of the other configurations.

 

[Tony Williams]

A few points re the original series of posts:

1. According to the info in the first post, the gun was an autoloader with a 30-round magazine. I suspect that the pilot being able to access the breech was to do with clearing a failure to feed.

2. The layout of the M-B design looks decided sub-optimal. Mounting the gun so far forward means that the balance of the aircraft would be altered quite significantly as the magazine of heavy ammo was used up. Variable weights, i.e. fuel and armament, are best placed as close as possible to the centre of lift.

3. What was supposed to happen with the fired cases? Presumably they had to be kept on board to avoid the risk of a large and heavy brass case striking the propeller, and that suggests considerable added complexity in the ammo handling and storage arrangements.