Bombing the Arras train...

[Pea_Shooter]

I noticed when bombing the train's cars (not the engine itself) the engine immediately begins moving at twice the speed. I guess it was designed to do that since it's not pulling the weight of several cars but I figure it should take a minute or two until it reaches that speed. Can this be fixed?

[Zooropa_Fly]

If you were driving along then suddenly came under fire...

 

Presumably it should take a steam train a minute to speed up significantly, but you know..

I think as far as 'fixing' it, there's a couple of other things ahead of this.

And yes - try to hit the engine car first !

 

You could always put this in as a suggestion to the devs in the GB forum section.

 

S!

[J2_Trupobaw]

IIRC steam engine outputs constant force (rather than constant power like combustion engine). With the mass / drag of train suddenly halved, couldn't it result in instant acceleration?

 

Liberator would know.

[BlitzPig_EL]

Steam locomotives don't do anything "instantly".  Early ones like the types we have from the WW1 period were not particularly fast.  The loco types we have are all pretty much small driver diameter freight movers, set up more to start a heavy consist, rather than attain high cruising speeds like say, a US passenger loco used for long distance runs.

[LukeFF]

2 hours ago, BlitzPig_EL said:

The loco types we have are all pretty much small driver diameter freight movers, set up more to start a heavy consist, rather than attain high cruising speeds like say, a US passenger loco used for long distance runs.

 

Correct, the locomotive we have in the game is the Prussian G 8, which has 1350 mm wheels: https://en.wikipedia.org/wiki/Prussian_G_8

[B24_LIBERATOR]

On 7/19/2021 at 1:24 AM, J2_Trupobaw said:

IIRC steam engine outputs constant force (rather than constant power like combustion engine). With the mass / drag of train suddenly halved, couldn't it result in instant acceleration?

 

Liberator would know.

It would depend on the number of driving wheels, size of the driving wheels, length of stroke, power to weight ratio, etc... basically all the same things that would pertain to an automobile or any other vehicle. My Jeep has a significant amount of torque but is also very heavy, step on the gas and it's 0-60 in about 10-14 seconds. 

The style of locomotive in the game is typically used as a freight locomotive, more torque but at a lower speed, if you're already running at speed then you most likely will not be accelerating very quickly as you are a lot closer to your maximum speed (they don't accelerate in a linear fashion).

Not having any of the IL-2 games so lacking first hand experience, if the OP is correct on the locomotive instantly gaining speed, I would agree with him that it's not realistic. If RoF is anything to go by though, I doubt anything will be done to fix it.

[Voyager]

Wouldn't it also depend on the friction available at the contact point, as well? As I recall, trains have low enough rolling friction that even wet leaves can screw it up?

 

Basically, I could see the acceleration doubling, but I recall the acceleration is pretty anemic on them at the best of times. 

[BlitzPig_EL]

When the New York Central's "20th. Century Limited" left the station at Toledo, Ohio, pulled by a J3a Hudson 4-6-4 locomotive, one of the best passenger locos ever built, it took it twelve miles to hit 100mph with the full consist of streamlined Pullman cars.  With that in mind it's safe to say that a locomotive with short drivers designed in the early years of the century for freight work would not sprint ahead if some or all of it's following cars became uncoupled.  It was cruising at close to it's top speed as it was.

 

 

The 20th. Century Limited, leaving Chicago, bound for New York City, where it would arrive 36 hours later, including stops along the way.  She picked up water from troughs between the tracks and the tender was large enough to hold enough coal for the trip.  They had to slow to 80mph to pick up water.

[ST_Catchov]

What an amazing machine! Architecture, planes, trains and automobiles were all about class and style back in them days. Today, it's kind of ... underwhelming.

[BlitzPig_EL]

During WW2 the "aerodynamic" streamlined casing was removed from the J3a fleet.  They didn't look as cool, but there was no loss in performance and it made maintenance easier.

[LukeFF]

One of these days I want to take an excursion pulled by this locomotive - it's based out of a museum maybe 15 minutes from my house: https://en.m.wikipedia.org/wiki/Santa_Fe_3751

 

 

Edited August 2, 2021 by LukeFF

[Avimimus]

12 hours ago, LukeFF said:

One of these days I want to take an excursion pulled by this locomotive - it's based out of a museum maybe 15 minutes from my house: https://en.m.wikipedia.org/wiki/Santa_Fe_3751

 

 

Do it!!!

[Avimimus]

During WWII it seems the standard procedure that developed was to slow the train when under attack, and make as much steam as possible in order to obscure the front of the train. Of course, if a tunnel or other cover was within easy reach sometimes trains might try to make for it.

 

Stopping does a number of things - it allows non-essential crew or passengers to disperse away from the cars, thus lowering casualties. It also makes it less likely that any derailment from the attack will propagate down the train - meaning that only the wagons directly hit will be damaged. Finally, it would provide a more stable platform for any anti-aircraft crews.

 

Also - I doubt damage would cause the crews to climb on the outside of the train and uncouple the damaged wagons... I think that the problem isn't really the physics of the locomotive remaining at the same speed - but rather the fact that the train instantly splits up (instead of derailing or being stopped by its crews or simply continuing und-erailed but badly on fire).

 

Anyway, it is also worth noting that trains weigh a lot and have incredible inertia. Traction is provided by just the very limited contact of the wheels on the rails - contact which is steel-on-steel (not the grippiest kind of bond). It is worth remembering that, if it wasn't for the fact that the steel tire of the wheels actually compress and bend slightly, the contact area of the circular wheel on the rail would be essentially infinitely small.

[BlitzPig_EL]

Those were excellent locomotives, especially after their rebuilds where they got 80" drivers and had their boiler pressure raised.  100mph running was not uncommon.