I am looking for the forums thoughts about using mechanical clip joints on EP belt 1000mm wide for a tunnel length of 11km with various horizontal curves with radii of 300m. Some curves over 90 degrees deviation from straight.

I have done many tunnels with tight curves for railways on all continents, but always with new and vulcanized belt/joints. The client on this particular project refuses to use new belt or vulcanized splices and has struggled to get to the current position (9kms) even with return and carry boosters. Now there are 4 return boosters and 5 carry boosters which have been necessary to reduce tension in the curves. Despite having the boosters I am struggling to track the belt through some of these curves and it is obvious when watching that some sections of belt do not track properly. None of the mechanical joints go the full width of the belt and I am of the belief that this is causing the problem tracking through the curve as tension is not transferred across the belt. The client complains about spillage and edge damage but what can you do when there are splices like this. (not sure if photo has been included) ■