Wear and Tear (1)

Sentinel 7109 has been hauling trains for nearly three years now and inevitably pulling 75 tons of carriages repeatedly up a 1 in 50 hill is going to ask a lot of a little engine.

Late in 2018, from time to time a knocking noise was heard from underneath and investigation showed that the main steam pipe had lost some insulation due to abrasion against a support bracket.

At the front of the water tank and just behind the rear engine, I had reinstalled the main steam pipe and included a support bracket using (from memory) existing mounting holes.

Main steam pipe with bright red support bracket.

The main steam pipe connects the regulator body to the 'Y' pipe fitting in the engine compartment. As far as I can tell from photos I took in 2004, there were no support brackets for the main steam pipe between its ends. This did not seem satisfactory to me and hence the addition of extra support.

However, not everything works out quite as anticipated and the bracket had been wearing the insulation allowing hard surfaces to knock together. The pipe clearly moves about when Joyce is in motion.

Worn insulation

On removing the bracket, it appears that the wear had not abraded the actual metal of the pipe but I'm glad I found it now and had not let it get any worse.

Metal exposed beneath the bracket location

It would appear that the bracket was too restrictive and probably with too small an area in contact with the pipe. However, I still want the extra support but with more give than it had.

I've wrapped some Aluminium-clad fibre glass sheet around the bracket to cushion the support from the pipe so that it is supported but not clamped.

Fibre glass cushion

Now to see how it behaves. (I have some other ideas if this doesn't last).