Re: 3801&3830

[Eddie Oliver <eoliver@efs.mq.edu.au>]

Neil O'Connor wrote:
> > 
> I was wondering about the difficulties of running two steam locomotives
> together. Like:
> - How do they ensure they are working together rather than against each
> other. For instance,
>   if the driver in the leading loco wants to to slow down how is that
> communicated to the
>   rear loco driver so he doesn't keep pushing "full steam ahead" so to
> speak?

The rear driver also knows the road, watches for signals etc., and will
generally drive much as he would do if he were on the leading engine.
There is only a problem when the driver on the lead engine (who controls
the brakes etc) plans to do something which will not be expected by the
second driver, in which case whistle or hand signals may be used.
However if the first engine eases off and the second doesn't, both
drivers will sense what is happening very quickly. It's an art and a
skill but not a miracle.

> - How do they get the powering right so they are both doing roughly half
> the work?

They don't necessarily. If the locos are of different types, the
technique will be to try to get each loco to work in its most "natural"
way, i.e. much as it would do if it were naturally hauling its just
proportion of the load. The problem only usually comes if either (a) one
crew is lazy or over-keen, or (b) one crew doesn't have a sufficiently
good judgment of the other loco's capacity (e.g. a small loco working
with a larger one can theoretically be given a hard time, but the
professionalism of the enginemen prevents this in all but drastic
cases).

There can be a sort of iterative process, where each driver drives as
"naturally" as he would normally, and then adjusts if it appears that he
needs to work harder or less hard, or go at a different speed etc.