Steam & Excursion > brakes

I thought I understood that tthe brakes are held off by the air system.  what then happens when air is lost and the brakes are not applied as in a runaway ?

dougd Wrote:
-------------------------------------------------------
> I thought I understood that tthe brakes are held
> off by the air system.  what then happens when
> air is lost and the brakes are not applied as in a
> runaway ?

What does this have to do with "Steam & Excursion"?  I believe you will find LOTS of information about railroad air brake systems, and their operation, by doing a search. Such has been discussed & explained many, many, many times on various boards here on TO.

In a nutshell ----

If there is no air connected to a car nor stored in its storage reservoirs, the cars air brakes are not operable and the car can only be held by handbrakes or mechanial means, such as chocking blocks.

When a train is first  made up and connected to a locomotive, the brake hoses are coupled together and the locomotive supplies each cars storage reservoirs, but this does not apply the air brakes.

If for any reason the brake pipe pressure is lowered below the pressure in the storage reservoirs, such as the engineer applying the brakes or an accidental break in the air line, a control valve on each car will direct air from its storage reservoirs into the brake cylinder(s), applying the brakes on that car, appropriate to the amount of pressure reduction in the brake pipe.

Any subsequent increase in the pressure in the brake pipe will cause a complete release of the brakes and will recharge the reservoir on that car.  Only certain passenger cars may have had special control valves that will partially release brakes, but this is found only on museum lines today.

-Larry Doyle
 



Edited 3 time(s). Last edit at 12/26/18 12:24 by LarryDoyle.

HotWater Wrote:
-------------------------------------------------------
> dougd Wrote:
> --------------------------------------------------
> -----
> > I thought I understood that tthe brakes are
> held
> > off by the air system.  what then happens when
> > air is lost and the brakes are not applied as in
> a
> > runaway ?
>
> What does this have to do with "Steam &
> Excursion"?  I believe you will find LOTS of
> information about railroad air brake systems, and
> their operation, by doing a search. Such has been
> discussed & explained many, many, many times on
> various boards here on TO.

You get a lump of coal in your stocking or something?  Relax, have some more egg nog.

Thanks Larry for your respone.

Per Jack's suggestion, see this post from awhile back....
https://www.trainorders.com/discussion/read.php?1,3147785,3147785#msg-3147785

In a nut shell, it all works on diaphragms, both engines and cars.  I am not speaking of the 1800s steam jams, :)





Nudge

I've been on this board for years and I really appreciate the clear and concise response to the question. I learn something new here almost everyday and I'm 82 years old!
 

Bill Deaver
Tehachapi, CA

Here we go again with the smart alac response. Why do we need tbese remarks again and again?

HotWater Wrote:
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> What does this have to do with "Steam &
> Excursion"?


Uh..... Do steam locomotives have brakes?????

Yes he may find more info elsewhere but maybe there is a reason he posted on this board.

It probably would have required less energy on your part to answer the question or simply ignore it instead of
Replying like that!

Posted from Android