The November evening started with the EGM, another possible record, now getting measured in seconds rather than minutes!
Nothing is to change we carry on into the new year with no increase in costs to the membership.
Our Chairman welcomed all, and the several guests we have with us.
I had a few words to say about our club evening subjects and the coming ones for 2025.
Guy then came on to talk to us about his favourite subject.
Water!
Well in this case boiling it and using it to drive a railway engine. First we had a basic drawing of what looked like my O gauge wind up railway engine from the early days of Hornby, but with flames and steam.
But this put us all onto the same page as Guy unfolded the various participants of the drawing.
However, nobody fell into the trap of what temperature does water boil at?! Guy continued to explain how the boiling point depended on the pressure and said we should expect a railway engine to run at 200ppsi. and the water temperature to be 198 degs C.
Energy was covered next using calories to measure it which Guy carefully explained.
Where does it come from?
Coal, and here we saw comparisons of where it was mined, the calorific value and water content, wet coal is bad news. Carbon combines with oxygen and hydrogen and can form sulphuric acid via sulphurous acid on the way. Not good news and careful control of the burning with air supply comes with experience in feeding and driving a railway engine.
Then we were shown how the heat gets to the water to form steam and where the steam is and how we can improve the efficiency by super heating and drying off the steam before use. The boiler and its problems of expansion, the need for strong stays to maintain its shape and the vagaries of bad coal and clinker build up.
The cylinders and valve system on use in models is not favoured for full size engines due to excessive wear but this valve gear was carefully explained. Then the more commonly used piston valve system as per full size.
The rate and amount of steam that enters the cylinders is carefully controlled so as not to waste any.
Guy went through raising steam and the necessary 2 ways of getting water into the boiler and the mandatory safety systems, including sight glass and safety valves and fusible links.
Steam injectors which some have thought of as black magic were explained and I am passing that one by!!!
I understood at the time but hesitate to explain.
The mystery Black 5!
But the wheel counters could see she was a 2-8-0 freight loco (8F).
Next the logistics of travelling from London to Edinburgh were looked at. It takes 9 tons of coal for the journey but 9 times the amount of water carried in the tender. This was solved by having water troughs on the way and scooping up the water without stopping. So the Flying Scotsman service was non-stop all the way.
The talk was well illustrated with slides and a video together with Guy answering questions along the way. Another interesting evening and Guy was thanked by all with a good round of applause.
We finished on time for once and our thanks go to the early bird members who put out the tables and chairs and cleared all at the end of the meeting. As always on call we had Jack and Neil supplying tea and coffee and biccys.
The presentation was videod by Rob and can be viewed here on the club's YouTube channel.
Roy
15/11/24