Whilst some people may struggle to grasp the scale and complexity of fitting ETCS, Rob Morland and his team have valliantly progressed the project despite assorted hurdles.  With support from Ian Greenan, Andy Meredith and David Wright, the start of the year saw the completion of the programme of electrical work at LMS.  This included the following jobs:

• Fitting the new 32mm fixed conduit to replace the life-expired flexible linking the centre frame stretcher box to the fireman’s side conduit system behind the battery box
• Pulling through the existing wiring loom and re-terminating all the wires
• Fitting the renewed flexible conduit to the lower centre marker lamp, wiring up the lamp and the forward-facing camera power supply
• Refitting the fixed conduit around the smokebox to the centre top marker lamp and wiring up the lamp
• Refitting all the frame-to-cab cabling
• Testing the shore power inputs to the Essential Services (ES) and Auxiliary Services (AS) supplies
• Fitting the headlamps and testing all the front lamps
• Testing the steam chest temperature gauge
• Running both turbogens on air and testing the Turbogen Switch Box tachometer and protection circuitry
• Testing all the engine electrical systems
• Testing the rebuilt sander indicator circuit on air
• Testing the atomiser steam indicator circuit

Andy Meredith made up the new 32mm fixed conduit to replace the previous flexible that connects to a box on the rear frame stretcher and passes through the frames just behind the AS Battery box to deliver cross-engine wiring into the cab.  The previous Adaptaflex flexible conduit had rotted internally due to ingress of slacker pipe water from the cab above.  We successfully pulled the existing loom through the new conduit and this was re-terminated on the two original connectors.

Work then moved to the front of the engine where Ian Greenan installed the lower centre marker lamp housing and lamp bracket, and the upper centre marker lamp housing and conduit around the smokebox.  The marker lamps were then rewired, the lower one includes the power supply to the forward-facing camera, which is located in the back of the marker housing.  A new flexible conduit was fitted for this, together with a set of elbows to allow connection into the existing conduit box port.  The refurbished headlamps were then refitted and all the front lighting systems were tested.  The wiring to all the tender lights was also tested through to the engine-tender umbilical connector.  The only fault found was with the hazard warning flasher relay to the daytime headlamp, which has obviously not survived its move to the new ES Control Panel.  Fixing this will involve a new flasher module.  The original one was the first electronic module built for the engine in 2008 and was ‘potted’ to avoid moisture ingress and protect against vibration, meaning that the relay can’t simply be changed.  Fortunately, a spare was built at the time, so this will be used now.

The next job was to test the re-located steam chest temperature gauge sensor circuit, now housed in the new Turbogen Switch Box.  This location avoids the need to run a dedicated thermocouple cable the whole length of the engine.  It now just requires the two wires that operate the meter in the cab.  These have been taken from our set of installed spares.  Placing the sensor in a cup of hot water registered 50 degrees C on the gauge, showing that this is working correctly.

Testing proceeded around the loco with all the essential and auxiliary circuits being switched on and checked.  All the auxiliary connections to the tender were tested through to the engine-tender connectors.  The Shore Power inputs on both sides of the engine were checked, and the cross-feeds between the ES and AS supplies were tested.  Everything worked correctly.

The next job was to re-connect all the wiring to the Turbogen Switch Box (disconnected to allow welding in the adjacent smokebox) and test the turbogens.  David Wright made up a new interface coupling which enabled the shop air supply to be coupled to the turbogen steam inputs.  We ran up the new turbogen, which was initially a little stiff and wouldn’t make full speed on the available air pressure.  However, it soon warmed up and, when restarted, ran at the correct speed under control of its governor.  After checking its output voltage we reset the over-voltage trip and were very pleased to see that it operated the new tachometer start-up circuit correctly, first illuminating the ‘Up to Speed’ LED and then around 35 seconds later the ‘Online’ LED.  This new delay timer allows the turbogen to fully stabilise before automatically connecting the electrical loads, which should reduce the amount of crew intervention needed when starting up the turbogens.  It will also automatically disconnect the loads in the event that steam pressure reduces to the point where the turbogen speed reduces below around 3000 rpm.

We then checked the feeds to the ES and AS I/O Panels and all was working correctly.  We applied loads and the turbogen powered these without a problem.  We then transferred the air supply across to the old turbogen (on the fireman’s side) and repeated the process.  This turbogen has been refurbished at DLW and fitted with a new turbine wheel, designed by Alan Parkin.  It also worked correctly, operating the tachometer circuit and supplying power to the ES and AS I/O Panels.  The tachometers showed the new turbogen to be operating at 3750 rpm (exactly according to the Meiningen specification) and the old one at 3700 rpm, which is well within its specified working range.  These tests demonstrate the full operation of the Turbogen Switch Box, so we can have a good level of confidence that the new two-turbogen system will work correctly when the loco is steamed.

We then proceeded to test the rebuilt sander indicator circuit.  This was connected up and the forward and reverse pressure switches were tested on air to check that they operated the flashing LED driver alert.  They both worked correctly.  David Wright will now arrange for a new bracket to be made up to mount the control box.  This is required as the old box mounted to the assembly that supported the TPWS Dual Cab Card enclosure.  With the installation of ETCS this has been relocated to a position under the driver’s seat, so the mounting position no longer exists.

Our final job was to test the atomiser steam indicator.  This illuminates a red warning LED on the AS Control Panel when there is no atomiser steam pressure, and a blue one when pressure is detected.  On connecting air to its steam input a fault was identified in the pressure switch.  It is located inside the frames below the smokebox on the fireman’s side and is exposed to a tough environment, so it has done well to work for over 12 years.  A new switch will be fitted.

Completion of this latest set of jobs means that the electrical work on the engine was approaching the finish line, with the only repairs needed being replacements for the headlamp flasher and atomiser steam indicator switch.  With the cab is permanently installed, we finally made all the wiring connections between cab and frames.  We also sealed the access hole between the cab and frames on the fireman’s side with a rubber gaiter and silicone, to prevent slacker water entering the conduit system.  We then ran a final check on all systems to test the repairs and make sure that nothing had been disturbed by the cab removal and replacement.  This completed the electrical work at LMS - the next tests would be carried out when the engine and tender had been coupled together at the GCR.