50026 Indomitable - Update 7th June 2003

One of the most important and difficult tasks in the rebuild of 50026 has finally been completed. That is the rebuild of the brake and air systems. This was the most difficult task we were faced with simply because virtually all the equipment and mass of pipework was all missing. Painstaking work over the last 18 months has seen the reinstatement of all the missing equipment, valves, gauges and pipework. The climax of this work led to a full air and "simulated" brake test taking place on 6/7 June 2003.

The loco is currently separated from its bogies whilst the ones ex-50001 are overhauled. We first therefore had to supply the loco with high-pressure air from an external source. Next the auxiliary reservoir tank was refitted under the loco and "plumbed in". External air from a large diesel compressor was then supplied to both the auxiliary and main reservoir systems. With some trepidation the air cocks were opened and 50026 had an air supply for the first time since she finished in BR service over 12 years ago.

Considering all the work that had been undertaken, very few air leaks were found and these were quickly rectified. In only ONE place where pipes found to have been fitted wrongly. This was where two control air pipes under the brake frame had been "crossed" over. Again this was soon put right.

Firstly all "control air" systems, such as the shutter blades, engine speedup etc where tested by toggling the EP valves by hand. All worked beautifully.

Next was to try a brake test using the refurbished no.2 end cab. Main reservoir was showing just over 100 psi (all that our compressor could manage) but this would be plenty. The M8 drivers brake valve was then unlocked and move round to "running". The satisfaction was great as the brake pipe charged up to 75 psi. This is slightly high but a simply adjustment of the M8 and we were getting the perfect reading of 72.5 psi.

Next we needed to test the Distributor which would mean actually applying the brakes. With the bogies disconnected we fitted a spare air reservoir on the end of the Automatic Air Brake supply pipe  to simulate the brake cylinders. This was only on no.2 end (hence the pictures of the gauges below only show readings for Bogie 2). We now hit our first problem. As we proportionally applied the brake no reading would appear on the Brake Indicator gauge. Nothing in First Application, nothing in Full Application. However, Emergency would give the correct ready of extinguishing the Brake Pipe and reading 70 psi on the Bogie Brake. It appeared therefore that the Distributor we had fitted had some sort of fault. A quick change to one of our spare distributors and joy of joy everything worked to perfection. Here is the evidence!!

After 12 years finally readings on the air gauges!! From left to right: Bogie Brake, Brake Pipe, Main Reservoir.

    First Application!!

    Proportional application.

    Further proportional application.

    Full Application.

Readings only show for bogie 2 as bogie 1 is isolated.

Finally the DSD was tested by toggling the magnet valve by hand. This worked perfectly therefore also proving that the overhauled Brake Application Unit is in full working order.

All in all a very satisfactory day!