Spitfire fuel gauge

[ShugNinx]

Hello !

 

I know there's been a lot of talk on this topic already (I'm on the keyboard binding bandwagon), but does anybody know why the heck it was historically designed that way ?

 

At first I thought it allowed to display the fuel level of two separate fuel tanks - top and bottom - on a single gauge by the use of a button, thus saving one gauge on the front panel. The upper tank being the first to empty, it's displayed by default. Fine, yet a toggle switch would have made more sense : once the upper tank is empty, switch to the bottom one permanently, what's the need to maintain the button to display the currently used tank ?

 

But I noticed the default gauge always reads '0' even with full tank, and then the written mention on the fuel gauge : "FUEL BOTTOM TANK ONLY. TOP TANK IS NOT GAUGED AND CONTAINS 48 GALLS. [...]"

Seriously ? Then why is there a button to display the bottom tank in the first place ? It's already a pain to only display the last 37 remaining Gallons, but THAT is seriously ill-minded designwise...

 

Side question : I imagine the gauge uses Imperial Gallons (~ 4,5L) and not US Gallons ?

 

Thanks in advance to the knowledgeable folks who'll take the time to answer me.

[Talon_]

Just remember this thing was designed in the 30s when you didn't have 100 years of automobile experience behind the common man gifting you with modern "common sense"! Why not have a switch for fuel gauge? You have a switch for guns and to cage your gyro! ?

[ShugNinx]

I guess there's much more to it than just the time period it was designed in and its inherent limitations. There's something really convoluted about this fuel gauge I'd like to know about.

[Art-J]

Fuel amount was measured by the means of a float. Don't know where in the bottom tank it was located exactly (don't want to go through drawings), but obviously it was higher or lower depending on the airplane attitude. Thus two scales on the gauge - upper is used while the airplane sits on the ground, lower is used while it flies level. Button being pressed turned electric gauge on, depressed turned gauge off just for the sake of minimizing current draw from electric system.

[RedKestrel]

3 hours ago, ShugNinx said:

Hello !

 

I know there's been a lot of talk on this topic already (I'm on the keyboard binding bandwagon), but does anybody know why the heck it was historically designed that way ?

 

At first I thought it allowed to display the fuel level of two separate fuel tanks - top and bottom - on a single gauge by the use of a button, thus saving one gauge on the front panel. The upper tank being the first to empty, it's displayed by default. Fine, yet a toggle switch would have made more sense : once the upper tank is empty, switch to the bottom one permanently, what's the need to maintain the button to display the currently used tank ?

 

But I noticed the default gauge always reads '0' even with full tank, and then the written mention on the fuel gauge : "FUEL BOTTOM TANK ONLY. TOP TANK IS NOT GAUGED AND CONTAINS 48 GALLS. [...]"

Seriously ? Then why is there a button to display the bottom tank in the first place ? It's already a pain to only display the last 37 remaining Gallons, but THAT is seriously ill-minded designwise...

 

Side question : I imagine the gauge uses Imperial Gallons (~ 4,5L) and not US Gallons ?

 

Thanks in advance to the knowledgeable folks who'll take the time to answer me.

You think the Spit is bad? At least the damn fuel guages aren't out on the wing, only showing the final 70l. Looking at you, Yak-1!

[BB5000]

If I'm not wrong, the fuel gauge switches between displaying the both tank's contents using a timer (simulating the button press that was needed to switch to the top tank). Can't verify it now, but I'm pretty sure that I've seen the fuel gauge switch between two readings without any input from me.

Edited November 28, 2019 by BB5000

[JimTM]

10 minutes ago, RedKestrel said:

You think the Spit is bad? At least the damn fuel guages aren't out on the wing, only showing the final 70l. Looking at you, Yak-1!

 

I'll take a quick glance out to the wing over flying straight and level for 10 or 15 seconds, waiting for the gauge to register, hoping that &@$#*%& Me262 doesn't blow you into little Spit bits any day!  

[Mac_Messer]

Funny enough, I was wondering similar thing about it since I`m in the midst of Kuban campaign.

 

+1 for the imperial/us gallon thing.

 

From me - is the 48 used first and then the 37 are used last or is it the other way?

28 minutes ago, RedKestrel said:

You think the Spit is bad? At least the damn fuel guages aren't out on the wing, only showing the final 70l. Looking at you, Yak-1!

I was going to say I much prefer it over the Spit gauge, then again 70L is not much.

17 minutes ago, BB5000 said:

If I'm not wrong, the fuel gauge switches between displaying the both tank's contents using a timer (simulating the button press that was needed to switch to the top tank). Can't verify it now, but I'm pretty sure that I've seen the fuel gauge switch between two readings without any input from me.

The black button next to the gauge is animated. If you look long enough, you`ll catch it being pressed to gauge the second tank.

 

BTW if it reads top tank is not gauged then it is not gauged, right?

[Art-J]

^ Yes, 48 is the upper tank and it just gravity-feeds into the lower 37 one, which feeds the engine.

[Mauf]

The Spit was designed as an interceptor, defense of Great Britain and such. Therefore, it was never intended to fly very long routes anyways. While the setup with the button and bottom tank only reading is clunky, it served its purpose. Technically, you don't need to bother with the state of the upper tank as it feeds into the lower. So as long the lower doesn't start draining, you know you got fuel in the upper left. The fuel load in the lower is more than enough to head back to any airfield in your area of operation (considering the interceptor role). As to why pressing a button: Think the floater that measures the fuel state gives wrong readings when the plane is not level. So the idea was: Pilot has to level plane for check and press the gauge button to get a reading. Why it's not permanently measuring I don't know (who cares so long as you read only in level flight), maybe Art-J is right and it was to reduce draw on the electrics.

[Ribbon]

Use chalk like Tom Hardy?

[Talisman]

I find it a big irritation in the Spitfire that the dev's have not allowed us to bind a key for the fuel tank button press, so that I can properly check the fuel gauge.  For me, this is a huge oversight to say the least.

 

This issue frustrates me every time I fly the Spitfire, especially when on MP and our CO askes for a squad fuel check and none of us can simply press the fuel check button

 

Come on dev's, please give us this fundamental functionality.

 

16 hours ago, Mac_Messer said:

 

The black button next to the gauge is animated. If you look long enough, you`ll catch it being pressed to gauge the second tank.

 

Look long enough and you lose your place in the squad formation or get bounced

We need to be able to bind a key to physically press to work the fuel gauge.  Having to stare at the bloody thing and wait is mad!

Edited November 29, 2019 by 56RAF_Talisman

[ShugNinx]

@Art-J@Mauf Thanks for your inputs guys. I realized I incorrectly assumed the working of this fuel gauge : I supposed it was meant to permanently display the fuel level of one of the two fuel tanks, and the switch was used to display the fuel level of the other one, when it was actually meant to stay off until the button is pressed to display the bottom tank fuel level only.

Of course, the plane needs to be kept in a level flight for proper reading, I've noticed the button isn't automatically pushed otherwise. 

 

 

1 hour ago, 56RAF_Talisman said:

We need to be able to bind a key to physically press to work the fuel gauge.  Having to stare at the bloody thing and wait is mad!

I strongly agree to this statement.

 

Edit : regarding the units, full tank is 386L according to the mission preparation screen, for a total of 85 Gallons, so that's indeed Imperial Gallons (~4,5L). Should have calculated this sooner ?

Edited November 29, 2019 by ShugNinx