23.11.2007, 19:40
If what you say is true! 
hock: Allow me to bow at your feet.
That done, these are my thoughts.
First, it is important to realise that train cars consist of multiple parts: You can set fire to a freight wagon but if it has a steel frame and bogies the only effect will be to destroy the top part of the car.
For this reason trains were often hard to destroy, with even P-47 pilots trying to kill the drivers in the cab. At the same time a train can be derailed by a very small piece of debris.
The nice thing is that we can model both hit points and, using the armour values, resistance to small caliber weapons separately. So we can, for instance, make a flat car very vulnerable to 20mm and almost immune to light machine guns and at the same time have a passenger car be more vulnerable to light machine guns but still take as many 20mm hits as the flat car.
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I can get real figures for some of these cars if you want (including for the actual makes modeled in Il-2), but it will take time. Below are my guesses off the top of my head. They assume two to four weapons of the caliber and it is important to remember that 3 seconds is a long time in combat.
Engine
- The boiler consists of curved sheet steel often exceeding half an inch (>120mm) in thickness. It is thus impervious to anything but powerful armour penetrating cannons. In addition locomotives has an extremely heavy frame.
- damage may cause engine to loose power and can kill the cab crew (train drivers) but the boiler is unlikely to explode even after multiple 20mm runs (12-26 seconds) essentially requiring the use of bombs or rockets or multiple strafing runs by several cannon equipped aircraft.
Tender
- short, relatively heavy, often with metal sides it should be resistant to 7.62mm rounds but vulnerable to a protracted burst of 12.7mm (8 seconds) or 20mm cannons (2-3 seconds)
passenger cars
- designed to be light weight with thin sides and a weak frame. A moderate run with 7.62mm (>6 seconds) should light it on fire, alternatively a short run of 12.7mm (3 seconds) or a few quick hits from a 20mm (1-1.5 seconds).
box cars
- the cargo on top can be lit on fire but the box will take a while to be destroyed. The frame is of medium strength. :. A long run for 7.62mm (>8 seconds), slightly resistant to 12.7mm fire (>4 seconds) and even 20mm fire (>1.5-2.5 seconds).
ammo cars
- like box cars but with explosive contents :. vulnerable to extended (>3 seconds) impacts by 7.62mm, a short burst from 12.7mm machine guns (2 seconds?) or a very short burst (>0.75 seconds) from HE cannon.
fuel cars
- these have contents under pressure and thus tend to be durable, although once punctured they are flammable. Virtually immune to 7.62mm (>12-18 seconds), extended rung by 12.7mm (>4 seconds) or a moderate run by 20mm (2-3 seconds)
flat cars (cargo)
- flat cars are just the frame :. no effect without damaging the frames badly and little debris to cause a derailing. So lets say a long run (8-10 seconds) for the 7.62mm, an extended run for 12.7 (5 seconds) and a short run for 20mm (1.5-3 seconds)
several variations exist:
- (cargo and tanks) might break more easily due to asymmetric load? Alternatively it might have a heavier duty frame.
- (trucks) the trucks could catch fire, otherwise no differences.
- (AA cars) like a flatcar but with a gun crew, the guns would be durable but the crew could be easily killed (and not as easily replaced as with static AA guns)
Ideally some cars should catch fire long before the train stops moving (not sure if this is possible).
hock: Allow me to bow at your feet.That done, these are my thoughts.
First, it is important to realise that train cars consist of multiple parts: You can set fire to a freight wagon but if it has a steel frame and bogies the only effect will be to destroy the top part of the car.
For this reason trains were often hard to destroy, with even P-47 pilots trying to kill the drivers in the cab. At the same time a train can be derailed by a very small piece of debris.
The nice thing is that we can model both hit points and, using the armour values, resistance to small caliber weapons separately. So we can, for instance, make a flat car very vulnerable to 20mm and almost immune to light machine guns and at the same time have a passenger car be more vulnerable to light machine guns but still take as many 20mm hits as the flat car.
--------
I can get real figures for some of these cars if you want (including for the actual makes modeled in Il-2), but it will take time. Below are my guesses off the top of my head. They assume two to four weapons of the caliber and it is important to remember that 3 seconds is a long time in combat.
Engine
- The boiler consists of curved sheet steel often exceeding half an inch (>120mm) in thickness. It is thus impervious to anything but powerful armour penetrating cannons. In addition locomotives has an extremely heavy frame.
- damage may cause engine to loose power and can kill the cab crew (train drivers) but the boiler is unlikely to explode even after multiple 20mm runs (12-26 seconds) essentially requiring the use of bombs or rockets or multiple strafing runs by several cannon equipped aircraft.
Tender
- short, relatively heavy, often with metal sides it should be resistant to 7.62mm rounds but vulnerable to a protracted burst of 12.7mm (8 seconds) or 20mm cannons (2-3 seconds)
passenger cars
- designed to be light weight with thin sides and a weak frame. A moderate run with 7.62mm (>6 seconds) should light it on fire, alternatively a short run of 12.7mm (3 seconds) or a few quick hits from a 20mm (1-1.5 seconds).
box cars
- the cargo on top can be lit on fire but the box will take a while to be destroyed. The frame is of medium strength. :. A long run for 7.62mm (>8 seconds), slightly resistant to 12.7mm fire (>4 seconds) and even 20mm fire (>1.5-2.5 seconds).
ammo cars
- like box cars but with explosive contents :. vulnerable to extended (>3 seconds) impacts by 7.62mm, a short burst from 12.7mm machine guns (2 seconds?) or a very short burst (>0.75 seconds) from HE cannon.
fuel cars
- these have contents under pressure and thus tend to be durable, although once punctured they are flammable. Virtually immune to 7.62mm (>12-18 seconds), extended rung by 12.7mm (>4 seconds) or a moderate run by 20mm (2-3 seconds)
flat cars (cargo)
- flat cars are just the frame :. no effect without damaging the frames badly and little debris to cause a derailing. So lets say a long run (8-10 seconds) for the 7.62mm, an extended run for 12.7 (5 seconds) and a short run for 20mm (1.5-3 seconds)
several variations exist:
- (cargo and tanks) might break more easily due to asymmetric load? Alternatively it might have a heavier duty frame.
- (trucks) the trucks could catch fire, otherwise no differences.
- (AA cars) like a flatcar but with a gun crew, the guns would be durable but the crew could be easily killed (and not as easily replaced as with static AA guns)
Ideally some cars should catch fire long before the train stops moving (not sure if this is possible).