Advice...vacuum or airbrakes?

You must have had an easy life at school. We had to state how many words we'd written and a sample was always checked. If you got the number wrong, you were in trouble, either for not writing enough or not counting correctly. Soon learned not to use apostrophies and plenty of adjectives!

 

Teachers must be lazier nowadays then! My best was an essay in 3 weeks late, half the requested word count, still got an A for it.

 

Amazing how the simplest skills are lost under the impact of technology... As anyone my age will tell you, handwriting varied far too much for volume to be a guide. You counted up the number of words in two or three typical lines, counted the number of lines (or typical number of lines per page for larger documents) and multiplied. Very quick and easy.

 

I'll add another factor here. If you have steep gradients, double pipe air should be a no brainer as the second line keeps the equalizing res's charge you will not loose your breaking power.....as alluded to earlier.

 

And, interestingly, that is exactly what North American railroads don't do. I suppose it helps if you have several hundred tons of diesel units on the front (and, in some cases, middle and rear) of your train with dynamic brakes in order to save using your air just to hold train speed on falling gradients but even so it takes skill and a bit of advance planning to get a typical North American freight down a hill. Of course it goes without saying that dynamic brakes bring with them a raft of new and unforeseen issues http://en.wikipedia.org/wiki/San_Bernardino_train_disaster Nothing to do with the original poster's question but an interesting read nevertheless.

 

Chappers, forgive me for being a pedant but I believe you mean it keeps the auxiliary rather than the equalising?