Spitfire's fuel tanks.

[RTHolmes]

sorry deleted the above as I got mixed up there with the XIV. as tested offline:


Mk. I, V, IX, XVI:
RL order: Upper (48 gal) -> Lower (37 gal)
AH order: BTM (44 USgal) -> TOP (58 USgal)

so although labelled correctly, the drain order is reversed, as you said.

Mk. VIII:
RL order: Wing (28 gal) -> Upper (47 gal) -> Lower (49 gal)
AH order: LW/RW (34 USgal) -> BTM (59 USgal) -> TOP (56 USgal)

again labelled correctly, but the drain order is reversed, as you said.

Mk. XIV:
RL order: Wing (26 gal) -> Upper (36 gal) -> Lower (49 gal)
AH order: LW/RW (32 USgal) -> BTM (44 USgal) -> TOP (58 USgal)

the drain order is correct, but the labels are reversed.


the Rear (31 gal) tank would be nice to have on the XIV too, but thats for another discussion

[dirtdart]

I always drain the top tank first on the IX.  I do notice it has less of a tendency to get into the ugly spit tailslide.  Probably psychosomatic.  A few years back someone explained tank order to me and since then I have just done it. 

On the eight I burn wing, then top. 

If carrying a DT I burn DT to climb alt thats it, then drop.  Just my personal TTP. 

Great post from the manual. 

[Krusty]

Almost no spits had the tail tank, as it was unsafe for flying. Especially when belly tanks could hold more than that.

I guess the question I have is: From the pilot perspective in the cockpit, can you select top and bottom tanks? Or was it just ONE option (i.e. "main" or "fusealge" etc)? Wing tanks appear to drain into the top, which appears to drain into the bottom... Can you even select them? Or was it all feeding the bottom tank and you NEVER switched the fuel selector (excluding drop tanks)?

[RTHolmes]

looks like switching between drop/mains/rears were the only 3 options. the left wing, right wing, upper and lower tanks function as effectively one tank, so shouldnt really be switchable (although they should be modelled as separate tanks for damage & mass reasons.)

[Guppy35]

What do you mean by "main"? A few years ago the top fuel tank on the Spit14 was labeled as main but now they made it like all other Spits, just top and bottom.
In AH's Spitfires the top fuel tanks is the largest, these diagrams show the top fuel tank to be the largest as well (excluding the Spit14).

BTW looking at the Spit14 fuel diagram it looks like the AH Spit14 has a screwed up fuel system. Apparently the real 14's bottom fuel tank was the largest (not the top as in AH) and we don't even have an aft tank.

The aft tank wasn't carried much if at all in wartime XIVs.  Same with the IX or XVI.

[RTHolmes]

yup Morgan states rear tanks only for the XIVe, which was only a handful of the XIVs, and it doesnt say if they were fitted to all of them. as I think you mentioned in another thread, theres hardly any photos of spits with rear filler caps.

[Karnak]

Modeling fuel leaks would be rough.  A leak in the bottom tank would gradually drain the entire fuel supply.  A leak in the top tank would drain fuel from the wing and top tanks, but not the bottom tank.  A leak in either wing tank would drain it, but not the opposite wing tank nor the top or bottom tanks.

I am not sure AH is set up to model that.

[Krusty]

No different from P-47s or 109s, where a leak means you lose all gas. The point where you get 1 effective tank, I mean.

I'm sure HTC can model it to do a hierarchical drain pattern.

IMO it should be set up that way. It's the finer details like this that make AH shine. Get a leak in the wing? Stops there. Get a leak in the bottom? You slowly lose it all. Mind you that bottom tank is more heavily protected, so it's not as likely as leaking from another tank.

[MachFly]

Modeling fuel leaks would be rough.  A leak in the bottom tank would gradually drain the entire fuel supply.  A leak in the top tank would drain fuel from the wing and top tanks, but not the bottom tank.  A leak in either wing tank would drain it, but not the opposite wing tank nor the top or bottom tanks.

I am not sure AH is set up to model that.

Yeah I don't see HTC modeling that.

[MachFly]

Mk. XIV:
RL order: Wing (26 gal) -> Upper (36 gal) -> Lower (49 gal)
AH order: LW/RW (32 USgal) -> BTM (44 USgal) -> TOP (58 USgal)

the drain order is correct, but the labels are reversed.

See the problem with this is not just the reversed labels but the fuel tanks are actually reversed. If you get hit in the top tank the one that is labeled "top" will start loosing fuel. So in AH the fuel tanks are physically reversed.

[MachFly]

Almost no spits had the tail tank, as it was unsafe for flying. Especially when belly tanks could hold more than that.

I guess the question I have is: From the pilot perspective in the cockpit, can you select top and bottom tanks? Or was it just ONE option (i.e. "main" or "fusealge" etc)? Wing tanks appear to drain into the top, which appears to drain into the bottom... Can you even select them? Or was it all feeding the bottom tank and you NEVER switched the fuel selector (excluding drop tanks)?

Looks like it's treated as one fuel tank.

from Pilot's notes for Spitfire IX, XI, & XVI




Every time they tell you which fuel tanks to select they call top and bottom tanks simply as "main tanks".




BTW if anyone wants the actual files send me a PM with your email and I'll email them to you.