Game Hurricane is 534 lbs overweight

[Kurfürst]

Originally Posted by *Buzzsaw*

I also checked the Spitfire IA to see if its weight is off. And yes, it is, by 107 lbs, or 49 kgs. The game Spitfire IA with Rotol prop and 100 octane is 2799 kgs, or 6157 lbs. It should weigh 2750 kgs, or 6050 lbs. You can see the weight listed in this document, which shows the weight of a Spit IA with Rotol prop, bullet proof glass and armour plating:

http://www.spitfireperformance.com/n3171.html

No, the Spitfire is all right, ours have armour plates modelled, which weighted about as much, the test you have shown simply does not have armor plates installed (which no Spitfire had prior to the end of May 1940). The so-called "armor plating over the tank" is in fact just a very slightly thicker aluminium plate over the fuel tank (its more like a deflector plate since it can really stop bullets unless they come in a shallow angle), but the aircraft lacks the pilot's back steel armor plates etc.

So the Spit weight is quite OK.

The Hurricane is well off, good spot.

[*Buzzsaw*]

Originally Posted by Kurfürst

The so-called "armor plating over the tank" is in fact just a very slightly thicker aluminium plate over the fuel tank (its more like a deflector plate since it can really stop bullets unless they come in a shallow angle)

Maybe you'd like to provide some proof for this assertion?

The weight added for the cockpit bullet proof glass and over tank armour is a total of 434 lbs, seems excessive if the armour plating was simply a thin sheet of aluminum. My understanding it was actual steel plate. I will be checking further references.

[JtD]

Originally Posted by *Buzzsaw*

The weight added for the cockpit bullet proof glass and over tank armour is a total of 434 lbs, seems excessive if the armour plating was simply a thin sheet of aluminum. My understanding it was actual steel plate. I will be checking further references.

Maybe you guys are talking about something different? The aircraft tested had so called fuel tank armour fitted already, and the overload condition was still on top of this.

[*Buzzsaw*]

Originally Posted by JtD

Maybe you guys are talking about something different? The aircraft tested had so called fuel tank armour fitted already, and the overload condition was still on top of this.

I realize the test aircraft L-2026 was equipped with the glass and plate. Kurfurst was making reference to the nature of the armour plate over the tank, suggesting it was just thin aluminum and not capable of providing much protection. My question was where his sources for that were, and why the weight was as much as 434 lbs if it was just aluminum.

[JtD]

We're not on the same page here.

L 2026 was equipped with a early production windscreen and armour plating over the fuselage fuel tank. In this configuration it was tested at a flying weight of 6316 lb.

In addition to this, the aircraft was ballasted an extra 434 lb in accordance with an Air Ministry letter, to be tested at overload condition of 6750 lb.

So, no - armoured glass was not fitted on the aircraft. Some sort of fuel tank protection was, but this has nothing to do with the extra 434 lb, as it already was installed.
Question - why do you think 434 lb is meant to simulate armour upgrades? Is that an assumption or do you have more background information?

[*Buzzsaw*]

Originally Posted by JtD

We're not on the same page here.

L 2026 was equipped with a early production windscreen and armour plating over the fuselage fuel tank. In this configuration it was tested at a flying weight of 6316 lb.

In addition to this, the aircraft was ballasted an extra 434 lb in accordance with an Air Ministry letter, to be tested at overload condition of 6750 lb.

So, no - armoured glass was not fitted on the aircraft. Some sort of fuel tank protection was, but this has nothing to do with the extra 434 lb, as it already was installed.
Question - why do you think 434 lb is meant to simulate armour upgrades? Is that an assumption or do you have more background information?

Salute

Just trying to determine facts here JtD...

I am not sure if you have more information, not suggesting you are incorrect, I had assumed the reference to the windscreen was to an bulletproof glass one, why else would they mention it, and the fact it was flush? The original bulletproof windscreens were fitted to the outside and protruded.

Not sure about the 434 lbs, did make the assumption it had to do with the armour planned to be added, not sure your assumption the aircraft weighed 6316 with the armour is correct, the weigh chart listed on Mike Williams site, (his adaption of the original) is not clear.

I am going to consult a copy of Morgan and Shacklady's book in next day or so to see if they can shed some light on the situation.

[JtD]

Originally Posted by *Buzzsaw*

I am not sure if you have more information, not suggesting you are incorrect, I had assumed the reference to the windscreen was to an bulletproof glass one, why else would they mention it, and the fact it was flush? The original bulletproof windscreens were fitted to the outside and protruded.

And I think because these bullet proof windshields were around, they found it necessary to mention that this was not installed on this aircraft. They also state that it is only the fuel tank armour that is different to L1547, which they tested earlier, and L1547 definitely had no armoured windscreen, as can be seen in the picture on the site. Also, the "early production" type windscreen as such was not armoured, and flush. To my knowledge, the Hurricane was never equipped with flush armoured windscreens, but then I might just not have seen it, yet.

[NZtyphoon]

Originally Posted by *Buzzsaw*

Maybe you'd like to provide some proof for this assertion?

The weight added for the cockpit bullet proof glass and over tank armour is a total of 434 lbs, seems excessive if the armour plating was simply a thin sheet of aluminum. My understanding it was actual steel plate. I will be checking further references.

A number of books on the Spitfire detail the modification to the fuel tank plating; viz 3mm thick alloy, not steel plate, which provided some degree of protection from small calibre bullets and shrapnel:



The weight of the armour plate behind and under the seat and behind the headrest was 73 lbs, so where the figure of 434 lbs comes from I have no idea.

[Kurfürst]

Originally Posted by *Buzzsaw*

Maybe you'd like to provide some proof for this assertion?

The weight added for the cockpit bullet proof glass and over tank armour is a total of 434 lbs, seems excessive if the armour plating was simply a thin sheet of aluminum. My understanding it was actual steel plate. I will be checking further references.

The Spitfire I carried a total of 51 kg armor. The said thicker (3.5mm)plating over the fuel top of the fuel tank was just 12.1 kg, the armored glass only 9 kg. Most of weight thus came from the numerous, bulky steel plates, most of which were however not terribly effective as they were rather thin.

109E armor weight was iirc 46 kg, that's essentially the weight of the large 8 mm thick armored bulkhead in the rear fuselage.

[NZtyphoon]

Originally Posted by Kurfürst

The Spitfire I carried a total of 51 kg armor. The said thicker (3.5mm)plating over the fuel top of the fuel tank was just 12.1 kg, the armored glass only 9 kg. Most of weight thus came from the numerous, bulky steel plates, most of which were however not terribly effective as they were rather thin.

109E armor weight was iirc 46 kg, that's essentially the weight of the large 8 mm thick armored bulkhead in the rear fuselage.

And where did a weight of 12.1 kg for the light alloy plating come from?

That the 8mm thick 109E "armour" weighed only 46 kg indicates that it was not armour plate, which would have weighed considerably more, but probably a toughened alloy of some kind, or a sandwich of armour and alloy. Then we have the usual assertion of how bad British methods were cf the uber German...