Nose wheel on Alco RS units

[Ed Kapuscinski]

While we are on this subject, there are some locos that have no visible brake.
I'm thinking like some U25Cs.

Like these:

http://www.rrpicturearchives.net/showPicture.aspx?id=2384172
http://www.rrpicturearchives.net/showPicture.aspx?id=2384163


If the brake is not external, where is it?

In the cab?   In the nose?  On the back like some SD40-2?

That is a really good question.
I have no idea, honestly.

I was looking for the chain and chain guard (that weird thing under the frame often seen on GE units see http://www.rrpicturearchives.net/showPicture.aspx?id=1905809) and don't see it.

Puzzling!

I have a hard time believing they don't have one, but EdsLaw.org exists for a reason.

[randgust]

While we are on this subject, there are some locos that have no visible brake.
I'm thinking like some U25Cs.

Like these:

http://www.rrpicturearchives.net/showPicture.aspx?id=2384172
http://www.rrpicturearchives.net/showPicture.aspx?id=2384163


If the brake is not external, where is it?

In the cab?   In the nose?  On the back like some SD40-2?

Wow, I've looked at a lot of photos, and I sure can't see it.   I can't believe there isn't a handbrake, but I've looked at other units, schematics, photos - on that era there was usually a VISIBLE cable or chain to the truck brake cylinders, which is a dead giveaway to the handbrake, and I'll be darned if I can spot it.   It's on other U25C's.   Even if you can't see it because it's hidden in the cab, somewhere there's a physical connection to the locomotive brake rigging at the truck and it's USUALLY pretty visible.    It was obviously a railroad option WHERE you put it, on the nose brake wheel, or a rachet, but the only other way to hold a shut-down locomotive would be to wheel-chock it..... seriously?

Yeah, Ed, I came to the same conclusion.    It's a serious trivia question here. 

EDIT:  This just in, both my resident GE expert and my locomotive expert confirmed that GE built the L&N and ACL units WITHOUT handbrakes.  Regs at that time considered 'securement' of a locomotive to be acceptable with a chain or similar physical restraint.   

I would have lost that bar bet.....

[SD452XR]

L&N GP30's were built without hand brakes.

[sd45elect2000]

While we are on this subject, there are some locos that have no visible brake.
I'm thinking like some U25Cs.

Like these:

http://www.rrpicturearchives.net/showPicture.aspx?id=2384172
http://www.rrpicturearchives.net/showPicture.aspx?id=2384163


If the brake is not external, where is it?



In the cab?   In the nose?  On the back like some SD40-2?

other side I've never encountered an engine without a hand brake.

[bbunge]

Chris:  Megantic was my first thought as well.

Kentuckian:  Modern automatic airbrakes are a little complicated ... As the pressure increases, the triple valve allows the air to fill the car reservoir.  The brakes are still released, as there's no pressure in the brake cylinder.

Nice simple explanation!  Also, as I understand it in case anyone is wondering, using this triple valve/reservoir system means a faster brake release with longer trains - you aren't waiting on the air pumped from the locomotive to reach to the end of a 80 car train, or end up dragging the last few cars. 

Bob

[peteski]

Every time I lay my eyes on the subject line of this thread, all I think it is that this is a discussion about some airplane with a tricycle landing gear.  Then, reading the posts where hand-brake is often mentioned makes me thing of another job I should not mention.   Sorry for this silly OT post, but I just had to say it. 

Also, all this really belongs in the prototype section of the forum.  See ya all there.

[nkalanaga]

Bob:  I don't know what the difference is, but yes, modern triple valves do allow faster train-line recharging. 

[Hawghead]

Bob:  I don't know what the difference is, but yes, modern triple valves do allow faster train-line recharging.

The air reservoir on a freight car is actually two reservoirs in one, the auxiliary and emergency reservoirs.  When the train line is recharging, some of the air in the emergency reservoir is dumped into the trainline to help it recharge faster.

Scott 

[Hawghead]

Some of the older UP units didn't have a manual hand brake.  The hand brake was applied and released by an electric motor controlled by a switch on the back wall of the locomotive.  If the brake couldn't be applied electrically, (non-running locomotive with dead battery etc.) there was what looked like a rack and pinion gear housing under the cab with a chain that attached to the brake gear.  There was a small handle in a holder that you could put on a square lug and if you turned the handle 2,753,621 times it would set the hand brake.  I had to untie and tie seven dead storage locomotives with these hand brakes in my consist once.  Also just because you can't see a chain doesn't mean the engine doesn't have a hand brake.  On some of the newer locomotives, the hand brake gear is under the locomotive and not visible.

Scott

[nkalanaga]

Scott:  Thank you!  Makes sense, as the emergency brake shouldn't be needed when the brakes are releasing!