[atsf37l]

Last ditch or not, if the prototype can do it - close throttle, apply sand, reverse, open throttle - then so should engines in ORTS. We should not be in the nanny business preventing our runners from doing stupid things through 'software locks'. Let the engines operate as per the prototype.

And regarding the flat wheels/cars derailing/slack running in arguments, we're talking situations here where you're gonna die if you don't do something! That other stuff is collateral damage.

JMHO. :jawdrop2:

[vince]

 Mike B, on 22 March 2015 - 01:53 PM, said:

Flat-wheel specials are also common on older streetcars (especially PCCs) and light rail cars........................................snip............................

How is this possible when the PCC's didn't use wheel brakes?
PCC's had electromagnetic rail brakes where an energized shoe bar was magnetically attracted the railhead. It can be seen mounted between the wheels on the trucks.

Also agree the reverser should be allowed when in forward motion as it is protypical AND was allowed in MSTS.
Best,
vince

[Kazareh]

Wish to put my echoing of the agreements made in here.

[Mike B]

 vince, on 22 March 2015 - 06:12 PM, said:

How is this possible when the PCC's didn't use wheel brakes?
PCC's had electromagnetic rail brakes where an energized shoe bar was magnetically attracted the railhead. It can be seen mounted between the wheels on the trucks.

Also agree the reverser should be allowed when in forward motion as it is protypical AND was allowed in MSTS.
Best,
vince

I've been on many PCCs with flat-spotted wheels, growing up in San Francisco. PCCs do have friction brakes on the wheels, in addition to the track brakes which are used for holding while the doors are open and for emergency braking. And in emergency braking ALL the brakes are used which can lock wheels. Some PCCs may have had dynamic braking (running the motors as generators into a resistor grid) as well.

Modern light rail cars are similar: most have track brakes for emergencies, and all have friction brakes for the wheels and regenerative (back into the power line) or dynamic (into a resistor grid) braking. Normal operation uses the regen/dynamic braking down to a low speed, then the friction brakes for the final stop. If near-maximum braking is required, the friction brakes are added to the dynamics, and the track brakes come on too for emergency braking. Unless anti-slip controls are present, locked wheels and resulting flat spots are very likely.

BTW, your Prius works much the same way, which is why 100K or more miles on a set of brakes is common. And as with the LRVs the proportioning between the brake systems is under automatic control, not the driver's. Some PCCs may have had manual control over the track brakes, too. But the track brakes are binary - on or off - so they are not used in normal braking for comfort reasons if nothing else.

Anecdote: on my commute, I had a driver one morning who started out late. Since the schedule at the time assumed the train ran at maximum speed between stations, and acceleration out of a station was always at maximum rate, there was no way to make up time. Or was there? Instead of normal braking, this guy screamed into the station at 40 mph, locked everything up, and slid to a halt right at the wheelchair ramp. Every time, for 5 stations. By that time, the brakes were smelling pretty badly and a few wheel thumps started to appear, even though they were the newer cars with anti-slip, but he made up almost 5 minutes. Luckily, this was at the outer end of the line where there weren't many standees yet (and those who usually chose to stand found seats after the first stop they experienced).

[vince]

 Mike B, on 23 March 2015 - 08:30 AM, said:

I've been on many PCCs with flat-spotted wheels, growing up in San Francisco. PCCs do have friction brakes on the wheels, in addition to the track brakes which are used for holding while the doors are open and for emergency braking. And in emergency braking ALL the brakes are used which can lock wheels. Some PCCs may have had dynamic braking (running the motors as generators into a resistor grid) as well.

.....................................snip save bandwidth.........................................................
Anecdote: on my commute, I had a driver one morning who started out late. Since the schedule at the time assumed the train ran at maximum speed between stations, and acceleration out of a station was always at maximum rate, there was no way to make up time. Or was there? Instead of normal braking, this guy screamed into the station at 40 mph, locked everything up, and slid to a halt right at the wheelchair ramp. Every time, for 5 stations. By that time, the brakes were smelling pretty badly and a few wheel thumps started to appear, even though they were the newer cars with anti-slip, but he made up almost 5 minutes. Luckily, this was at the outer end of the line where there weren't many standees yet (and those who usually chose to stand found seats after the first stop they experienced).

Thank you for explaining. Your commuter anecdote . . . I experienced much the same in the early days on the E Train R42 cars in New York where the norm was flat wheels all the time..

best, vince