The Loco is derailing on time for scouse at 105 yards from the 'stop at could loader' instruction, Loco is just before the points where the train jumps of the tracks
Here is the solution that I discovered to complete the Scenario.. Instead of reversing directly to the coal chute. Keep to the right on the points (switch) so that you are reversing up the return loop (as indicated by my dodgy green line) until you reach the buffer stop. This enables you to approach the coal chute from behind, preventing the derailment. Even though this bug has been reported many times DTG says that it doesn't happen. Even when you send them screenshots and video footage of the loco going into orbit!
The other thing that you can try is hitting the point at around 10mph and not at a low speed, as I show in my video below.. Just a quick note: During my testing this method isn't 100% but it does work. So before you reverse up to the Coal Chute save the game. This will avoid the need to restarting the scenario. If it derails try again and hopefully this time it will work!
When I first ran Time for Scouse, I got through coal & water refueling without problems, but eventually ended the session without saving (why? I don't know). When I loaded the scenario a couple of days later, this happened as I drove toward the coal loader: Wow! I did find a way around this by opening Steam, deleting the Spirit of Steam route and then reinstalling it. After restarting TSW3, I was able to complete Time for Scouse successfully. I hope that DTG will take a look at this derailment issue and find a way to eliminate it from the fine collection of shunting activities included with this route. {BTW: my fear of taking on a steam locomotive kept me from buying Spirit of Steam with TSW3 originally, but thanks to good experiences with the Peak Forest route and a generous recent DTG sale, I was able to acquire Spirit of Steam for a v-e-r-y low price.)
And still there is an issue with this. I made through the majority of the scenario. After leaving the turntable, headed back to edge hill. I stopped at the end of the line, set the points and reversed. Stopped, set the point and moved forwards, and I derailed on the points. I started from the check point (Turntable). This time making sure to have a good look as I went over the points. The 3rd large wheel set just can't make the turn. I was able to repeat this several times. I took a couple of screen shots with the inside wheel completely off the rails. I eventually gave up trying and reversed down the line. Cut through the engine shed and reversed in. This was on TSW4 PC
Yeah annoying, I had derailment problems at the start of the scenario, before the Coal Loader, and at the end of the scenario, before the Stop & Reverse (after the wrong path routing). The solution in my case, I followed the advice from elric#1386 to cross the points at goldilocks speed, not too slow & not too fast. 10-12mph worked for me many thanks elric#1386 I am on PC/TSW4, and curiously, I had no problems with any SOS scenarios or journeys on PS5/TSW4 which were all completed. I'm running out of time to complete all the remaining SOS scenarios and journeys on PC/TSW4, before TSW5 may break them all. LOL