Part 1 & 2 have been drafted for quite a while and I only got round to finishing them off. So if you haven’t seen them yet then view them here, Part 1, Part 2. What will probably happen is that this post will end up doing the same. So this is YEC 1382 ‘Unittie’ The Long Term Project, Part 3.
Preparation for Power Tests
Once we got the engine running on the loco, work started in preparing the control system, generator and traction motor for power tests.
This started with the comutators on both the generator and traction motor being cleaned and the excess carbon removed from between the sections. The brushes were also all removed and the holders/sliders cleaned to ensure they all moved freely to ensure a good contact.
While this was going on the control system was being tested (with the engine not running). This was to ensure that the contacts all operated correctly. Obviously we knew the starting circuit worked correctly as we have had the engine running.
The Voltage regulator was also checked over for any obvious damage. This was because the charge gauge was showing that the batteries were not being charged when the engine was running.
Nothing obvious was found so further investigation was required.
Before power tests started the brake rigging needed to be refitted now it had been cleaned. It was noted that the bushes in the brake hangers and the pins on the bars were heavily worn and would need replacing in the near future.
With the brake rigging refitted the time come for power tests.
Unfortunately, the first attempts didn’t go well. The control circuits worked perfectly. The contacts closed, the engine rpm rose…..but nothing happened. For some reason no power was getting to the traction motor.
Over the follow few evenings more fettling and cleaning was done. The outcome of which was only a slight improvment but a good sign that we potentially had a working loco.
What had been achieved was that with the engine running at full speed the loco would crawl along (about half walking speed, maybe less). This showed us that the electrical connection were working ok but for some reason power was not being generated correctly.
It was at this point we got hold of an electrical wiring diagram and upon studying this, noticed that the dynamo gave a feed to the generator windings. Knowing this and knowing that there was a charging issue it was believed that the two problems had a common cause. The dynamo was tested and was found to have no output. So this was removed along with the voltage regulator and sent to be repaired.
Cosmetic Restoration (Preventing the rust)
While this was being repaired work started on the cosmetic restoration. This was more preventative repairs at this time to stop the progression of any rust etc…
Here are a selection of images from this restoration.
Power Tests Cont…
News come back that when the dynamo was tested again at the repair company. This time it was found to be working perfectly. So after a bit of thinking it was agreed that because the dynamo had been stood for such a long time the electromagnet inside the dynamo had lost all its residual magnetism. So there was nothing there to kick start the generation of electricity.
We believe that when the dynamo was installed on the testing machine the windings were energised just enough to create enough of a magnetic field. This allowed the dynamo to start generating as it should. The residual magnetic field stays in the dynamo windings long enough for it to be still there the next time you start the loco but not if it has been stood for 10 years in between.
Now when the dynamo was re-fitted to the loco, the engine was started and the batteries began charging. This also meant the field windings in the generator were also now being excited by the dynamo and was able to generate the power it should. This is what resulted….
1382 Then went on to run a number of trips round the Steelworks at Scunthorpe as proving runs before being stripped down for the restoration.
Hopfully Part 4 will come soon where the main restoration will begin.
A lot of the work you have seen here wouldn’t of been possible without help from members of the ID&RPG.