MICK Oliver's concerns about the heath and safety of rail trackside workers ['Trackworker safety concern', Letters, March 12] is one of those situations that takes time, unfortunately, to improve, owing to the length of life of older rolling stock.

The trains he refers to are 20 years old and were among the last to be built for service in the UK with direct discharge toilets.

However, 'relief'is at hand with the introduction of new units with chemical retention toilets, which should all be in service by this summer,after which no main line trains stopping at Harrow and Wealdstone will feature the disgusting old system.

However, in passing, it should be mentioned that the new trains have a very powerful vacuum emptying system and the notices not to operate the flush while seated should not be ignored.

In some newer trains the flush button is deliberately located behind the raised seat cover as a passenger safety measure, so while the health of trackside workers will improve, the risk moves to the passenger.

MICHAEL READE

Clonard Way Hatch End