News at MeierMotors GmbH / Bremgarten South Germany

[hampden98]

Why are the wing fuel tanks sunken in?
Are they flexible like rubber?
I'd always imagined they were metal.

[DazDaMan]

Are they not wet wing fuel cells?

[Bruce]

They are 'rubber' tanks. Most have a foam filling now, but it looks like these are a bit older.

Fitted a few of those!



Bruce

[Al Elliott]

Probably of the self-sealing type...

http://en.wikipedia.org/wiki/Self-sealing_fuel_tank

Al

[Bruce]

Matthias - what Mark is the engine? Looks like a 100 series Merlin from first glance.



Bruce

[Bruce]

They arent self sealing these days!

[hampden98]

Aren't WW2 self sealing tanks metal surrounded by layers of rubber?
So, what does a WW2 Spitfire wing fuel tank look like, made of? (just out of interest).

[Seafuryfan]

Fuel tanks are made of flexible material to take account of changing atmospheric pressure. The air in the tanks must be able to expand if the air pressure rises. Similarly, as air pressure reduces, the tank walls will contract. This ensures that air pressure is equalised throughout the tank system and fuel can pass freely between the tanks to the engine, if required with a little help from a fuel booster pump (which is a often located within the tank on more complex systems).

[Avro Avian]

Aren't WW2 self sealing tanks metal surrounded by layers of rubber?
So, what does a WW2 Spitfire wing fuel tank look like, made of? (just out of interest).

Not necessarily metal tanks. Sure, the Spitfire main fuselage tanks were Al Alloy, covered with the "self sealing" material, but fuel tanks can/were also made out of rubber, eg the Mustang. The basic principle of a 'self sealing' tank is to have three layers; an inner and outer layer of fuel resistant material (synthetic rubber or metal), and a middle (sandwiched) layer that reacts to the presence of fuel, ie it swells on contact, thus blocking off any holes made by bullets, etc. Off the top of my head, I believe the wing tanks an the wartime Spitfires were rubber. What you see in Matthias' terrific photos is relatively recent modification to put fuel cells in the gun bays to extend the two seater's fairly woeful range - one has to remember that the front cockpit was moved forward (9"?) and consequently the fuelage tanks' capacity was reduced.

[danjama]

Not necessarily metal tanks. Sure, the Spitfire main fuselage tanks were Al Alloy, covered with the "self sealing" material, but fuel tanks can/were also made out of rubber, eg the Mustang. The basic principle of a 'self sealing' tank is to have three layers; an inner and outer layer of fuel resistant material (synthetic rubber or metal), and a middle (sandwiched) layer that reacts to the presence of fuel, ie it swells on contact, thus blocking off any holes made by bullets, etc. Off the top of my head, I believe the wing tanks an the wartime Spitfires were rubber. What you see in Matthias' terrific photos is relatively recent modification to put fuel cells in the gun bays to extend the two seater's fairly woeful range - one has to remember that the front cockpit was moved forward (9"?) and consequently the fuelage tanks' capacity was reduced.

Would that also be the reason for an adjustable CoG?

[Mark12]

Spitfire wing fuel.

The PR Spitfires had a 'wet' wing forward of the main spar as modern airliners.

The later marks of Spitfire, the VIII and the Griffon powered XIV were desperate for more internal fuel. One of the reasons why the Mk VIII was late to production was that the wing was substantially re-designed and strengthened including the placement of a small accessible 12.5 gallon fuel tank in the leading edge. This tank, to the best of my knowledge, was a welded alloy construction covered in self sealing rubber sandwich as per the construction of the later lower main fuselage tanks.

The tanks we see today in the former gun bay locations are the product and technology of 1980's racing cars, where the odd bullet penetration was not part of the design brief.

Mark

[Bruce]

The drawings for the wing tank conversion are original spitfire type 509, and as far as I am aware were standard on the originally converted 2 seat aircraft. They would have been rubber tanks of some type, but earlier technology than shown here.

I did have an original seafire leading edge tank, which was of the rubber self sealing type, and not covered aluminium.


Bruce

[Mark12]

I did have an original Seafire leading edge tank, which was of the rubber self sealing type, and not covered aluminium.


Bruce

The reason why I believe the newly introduced leading edge tank on the VIII/XIV wing was rubber covered aluminium is based on the logic that the Mk VIII introduced the unique top fuselage tank at the same time. This top tank was welded aluminium with rubber self sealing and secured by the clamping of the top tank armoured cover, as appears to be the securing mode for the wing tanks. This style of upper fuselage tank was unique to the MK VIII and abandoned on subsequent marks that reverted to the single curvature rivetted construction.

The upper fuel tanks in the rear fuselage, introduced to extend the range, were also welded aluminium and self sealing.

It is a long time since I saw the main tank of a type 509 post WWII conversion. Here the top and bottom tanks were replaced with a single dedicated unit with built in struts to compensate for the removal of the diagonal bracing struts located between the top and bottom tanks on a conventional Spitfire. Something in the back of my mind says these tanks were made of resin bonded material. Can anybody confirm?

Mark

[markstringer]

Great updates as always Matthias.

Are there still a couple of Me 109 / buchon projects knocking around there, and if so what if any progress has been made?

[Bruce]

The upper fuel tanks in the rear fuselage, introduced to extend the range, were also welded aluminium and self sealing.Mark

I've only ever seen rivetted upper rear fuselage tanks, though the lower ones were welded!

As I say, the Seafire leading edge tank I had was rubber, but may well have been different!!


Bruce

[Matthias Dorst]

some detailwork, Jochen at work



teamwork with Julian



the brandnew propeller sits in place



bodywork, the Spitfire needs and gets new cowling. Some work for the team

[Beaufighter VI]

The drawings for the wing tank conversion are original spitfire type 509, and as far as I am aware were standard on the originally converted 2 seat aircraft. They would have been rubber tanks of some type, but earlier technology than shown here.

I did have an original seafire leading edge tank, which was of the rubber self sealing type, and not covered aluminium.


Bruce

Correct Bruce, the leading edge tanks were classed as "semi rigid" construction being of rubber and fabric, not aluminium.

[Mark12]

Correct Bruce, the leading edge tanks were classed as "semi rigid" construction being of rubber and fabric, not aluminium.

Happy to stand corrected.

Mark

[proplover]

PT462 has bag tanks in the gun bays and PR type leading edge fuel tanks. The gun bays are rubber bag type which are foam filled. I understood the bay tanks were bag style as due to wing flex a metal tank would eventualy crack (down the wealds) as I belived happened to the Bayliss T9 last year. This one has now got rubber bag tanks.
If thats so I do wonder about the PR tanks, these appear to be a vast metal void in the whole of the wing leading edge! I believe there are simple baffels internally but they are certainly not foam filled. Hence the aircraft is not cleared for any aerobatics with fuel in the PR tanks, indeed they are refered to as ferry flight or transit tanks.
All up this Spitfire will hold some 210 Imp gallons - Been in it when taking off with some 150 gallons on grass - it was HEAVY!

[danjama]

Thanks! Very cool

[TonyT]

Most PR tanks hadn't been used for years which was what was causing a lot of the problems of late with sealant and seals on fastners drying out and the fastners working loose, hence most are now removing the tank facility as such, but will look externally correct.

[Matthias Dorst]

NEW PROJECT at the MeierMotors shop. This time its the restauration of a Hispano Aviacion Buchon to a Messerschmitt Bf109 G. Basis is the WkNr133, last reg N109FF. Owner of the project is Jerry Yagen and his Fighter Factory. I think this will be a fantastic project !



What do you think ? Should I open a new thread concerning the Buchon project, or should i post the updates in this MeierMotors thread ?

[Elliott Marsh]

I'd be all for a new thread, looks like another awesome project!

[DazDaMan]

I think you should just keep all the updates in the one thread, but that's just my opinion...

[ian_]

Just keep posting! Your photos are always superb, many thanks for putting them in the public domain.

[James D]

Great news! I always wonder where they turn up DB motors for these things.

[Seafuryfan]

Same thread please for me Matthius. Keep up the good work - very informative with great photos.

[jimbob1194]

Looks like another cracking project. Finally joined this forum after watching this topic very closely. Top work as normal!

James

[ZRX61]

Most have a foam filling now,
Bruce

"Explosafe"

[OHOPE]

Please keep it all in one thread .