I have what may be a dumb question

[thor]

Over on one of the other forums there's a chap who posts pictures of 'lash ups' and I gather - perhaps mistakenly - that there are problems associated with trying to get two engines to work together.  Why?

In the past, in H0, I've occasionally done this for particularly long, heavy trains and cannot recall its being particularly difficult to do though you couldnt just connect any two, you had to find two that would work together with the faster one up front.

So what is it with 'lash-ups'?

[csxt30]

I haven't seen the subject on the other forums yet, but in the 1990s & recently when I started again, I have been doing a lot of lash ups. Now this is with Lionels' TMCC, & I found the engines had to run pretty evenly apart & I had to follow the directions to program them, exactly. Are you talking about conventional mode ? My lash up now is with an MTH diesel & an Atlas diesel, & both have TMCC in them & run close to the same when seperated, almost exact. I bought both of them used & have not had any problems, yet !! I think the key is that they both have to have the same gear ratio or be 2 or 3 engines, identicle.

Thanks, John   

[lionelsoni]

The main problem is that the e-unit will occasionally step on one locomotive and not on the other(s).  Then it is a real pain to get them back into synchronization.  Short of separate control of the locomotives, TMCC or whatever, it helps to bus the pickups between locomotives.  The definitive cure is to run all the motors on a single e-unit; but that requires a multiwire tether.