The principle of "short cycling" is to make relatively light sets with as short a hold as possible. You want to make a set that will slow the train, release the brakes and let the air being held in the brake cylinders by the retainer hold the train while the auxiliary resevoirs on the cars recharge.
Making a lighter set, and riding the set until it slowly brings you speed down can get you in trouble because when you do release the brakes, there is less pressure in the brake cylinders to begin with and therefore the pressure needed to hold the train back in released sooner, the train starts to accelerate sooner - before the auxiliary reservoirs recharge fully. Next thing you know, you are in trouble.
Modern day railroaders are tought to "balance brake" where you set air a little at a time until you balance the braking effort with the grade. If you do this, then release the brakes and expect the retainers to hold you back - it ain't gonna happen....
The same lessons we learned on Cumbres work on La Veta, which is one reason the old heads would say if you can run a train off Cumbres, you can run a train anywhere. We make sets of 6-8 lbs - a minimum reduction on a #26 brake valve (or perhaps a bit more) - does the trick. In some places, you release the brakes as soon as the air stops blowing out the exhaust. Then 10-15 seconds later the train will begin to slow. The big thing we have to deal with on La Veta is getting the composition brake shoes warmed up before you top the hill. Coming up to the summit we put a minimum set under the train and drag it up to the summit, stop, put the retainers up then creep over the top. As you get the train over the apex, make 3-4 minimum reductions with short holds to get the air pressure building up in the cylinders. As the train comes over the top, you make a 8 lb set, throttle the engines back, change over into dynamic braking, gather the slack up against the train, get about 300 amps of dynamic brakes against the train (about throttle 4-5), and hang on to it until the speeds starts to drag down below 10 mph, then release the air, keeping the dynamic brakes in the same position. I assure you every engineer has to deal with a bit of "pucker factor" every time they top the hill wondering if the brakes are going to hold as it takes a miniute or two for the brakes to warm up and begin holding properly even after we drug them up the hill the last 1/4 mile. With 4-6 units in the consist, you have to dynamic brakes to hold them back and to assist in the braking effort. Additionally, it is no longer a federal requirement to inspect retainer valves and ensure they function correctly. I doubt there are very many other railroads in the country that use them like we do. It is not uncommon to get down to La Veta and find cars in the train that had a non-functioning retainer, meanwhile the other cars are engulfed with blue brake shoe smoke. In the winter, when you roll through fresh snow, the snow gets on the wheel treads and boils off in a cloud of steam.
