Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question


John Stutz
 

Dave

This use by railroaders of "tie down" and "tie up" is a matter of historic linguistic conventions, borrowing and tradition.  In the society where railroad traditions and vocabulary initially developed, almost two centuries ago, when "to tie up" was used regarding any form of transportation, it was understood to mean taking measures to prevent its drifting or wandering off.  Horse folk and boaters still use the phrase in its original literal sense, but the wider generic sense of preventing something from unwanted motion was then and is still somewhat current.  This is how railroaders used it, when they borrowed the phrase and extended its application to the measures needed to keep set out railroad cars from moving.  To "tie down" cars or a train was a natural addition to the railroader's vocabulary, since everyone understood what was meant, and this is how they use it today.

The standard RR hand brake of circa 1900 employed a vertical shaft with a wheel fixed at the top for turning the shaft, a drum at the shaft's bottom on which a chain could be wound, and somewhere in between, a circular ratchet on the rod, which could be locked with a loose pawl to prevent the chain's unwinding.  The chain attaches to a rod which in turn pivots on the floating brake lever adjacent to the brake piston's push rod.  Winding up the chain applies the brakes the same way that air pressure in the brake cylinder does.  When the chain was wound up tight, and the pawl engaged in the ratchet, the brakes are locked on and the car is "tied down".

John Stutz

On October 10, 2020 at 3:22 PM Climax@... wrote:

I'm curious about a term.  I see the word "tie" used.  Are they actually setting brakes and using some sort of rope, cord, or chain to hold them in place or is that a term which means they brakes are hand set?
Dave

-----Original Message-----
From: "Curtis Brookshire via groups.io"
Sent: Oct 10, 2020 6:14 PM
To: HOn3@groups.io
Subject: Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Yes, it's the vernacular of railroading. Crews "tie down" a train by applying hand brakes and in some situations chocks. Crews "tie up" when they put off duty.

To answer some other comments: the number of handbrakes to tie depends on the weight of the train, the grade and efficiency of the handbrake. On a certain Class 1, rules require 1 brake for 1 car; 2 brakes for 2 cars and a sufficient number beyond that. On a certain short line it's at least one brake for 10% of the consist, plus any more required to hold cars on grade. Rule of thumb is to tie a sufficient number of handbrakes and then test them to see that they hold. In the HOn3 world a pin, fishing line or just a stiff, poor rolling car may be sufficient. Reference brake pipe pressure: current broad gauge roads use 90 lbs on freight trains, Amtrak uses 110 lbs. Steam powered narrow gauge in the day used less, maybe only 60 lbs. I don't know what current narrow gauge operations like CATS, D&S or EBT uses on theirs. Anyone connected with them know the answer?

Curtis Brookshire
Pine Level NC

 

Join HOn3@groups.io to automatically receive all group messages.