Haulage capacity

[StevieB]

Over on rmweb, in the Wright writes forum, there is periodic discussion about the haulage capacity of RTR/kit built locos, in particular steam. Tony Wright’s depiction of Little Bytham on the ECML runs passenger trains of 12+ carriages and his kit built locos have no trouble with this but put an RTR loco on the front and it struggles. Has anyone tested what MM’s locos can haul and, in particular, whether a pair of 141/181’s outperforms an 071. In reality that was the case with power coming through 8 wheel sets rather 6.

Stephen

Edited October 24, 2019 by StevieB

[Mayner]

I can't comment on the Murphy Models diesels but I found that a single 4 axle unit performed better than a single 6 axle unit in N Gauge. The 6 axle units tended to slip and loose traction with a load of 12+ freight cars while the 4 axle units just plodded along. There was a tendency for the outer axles of a 3 axle power bogie to loose traction as the bogie rocked back and forward pivoting about the center axle.

I used a mixture of Kato and Atlas American diesels and usually loaded to 15-18 freight cars with 2-3 locos but sometimes loaded up to 50 cars with 4-5 locos, coupling strength/adjustment was the limiting factor on train length rather than haulage capacity. 

The situation with the haulage capacity of kit Vs rtr locos on large layouts is an interesting one, large kit built locos used on layouts like Little Bytham or Retford usually had heavy whitemetal or composite whitemetal and brass bodies with all metal chassis and running gear (sometimes plastic centered wheels) powered by large can motors with double reduction gearing designed to run at scale speed. 

Kits like the DJH Brittania, Austerity,  8F or 9F were more expensive than buying a equivalent rtr model but mechanically bullet proof once assembled avoiding problems with metal fatigue, split gears and failed pick-up systems that plagued many of the rtr steam locos introduced during the past 20 years

Edited October 24, 2019 by Mayner