Overhaul work on the Class 89 has continued; the locomotive is now complete following the installation of the Field Convertors, Rheostatic Brake Stacks and associated works by both HNRC staff and ACLG volunteers.
The Field Convertors have been rebuilt, tested and installed into the central section of the locomotive. The rebuilding and testing of the Field Convertors has been an extensive project with the convertors progressing from a tested prototype to tested first off production unit before work commenced on building the other five Field Convertors. Once the six Field Convertors had been assembled into the two cubicles the assemblies were bench tested before being installed into the locomotive. Testing of the Field Convertors onboard the locomotive initially focused on synthetic operation using local controls on each convertor before connecting locomotive’s Microcontroller and the Field Battery. Ultimately tests have been undertaken to prove the entire field control system from the Driver’s controls through to Field Current output into the Traction Motor Field Windings. The rebuilt Field Convertors include visual displays that provide information on their status and operation which allowed their operation to be checked as other systems on the locomotive operated.
The locomotive’s Rheostatic Brake Stacks have been rebuilt with new support frames and cowls to suit the Class 86 style fan motor and fan. Both Brake Stacks have had damaged resistor elements replaced. New Brake Stack mountings have been fabricated inside the locomotive.
The locomotive’s Field Battery has been rebuilt, the compartment was stripped of all the old cells, which had been removed of as they would not hold their charge, cleaned and new cells installed.
The locomotive Surge Suppression network has been fitted with new capacitors of a higher voltage rating. Once the new capacitors were fitted the Surge Suppression network panels were cleaned and tested before being lifted into the central section of the locomotive.
Repairs have been undertaken to both access panels and joints in the locomotive roof to ensure that it seals correctly. Once the locomotive roof sections were all bolted in place internal wring runs along the equipment room ceiling were reinstated and tested. The equipment room air handling system has been reinstated. The interior of the locomotive has been cleaned, with attention paid to insulators and the interior partitions for high voltage areas reinstated. With the locomotive complete the earth bonds for the roof, Field Convertors and Brake Stacks have all been inspected and tested.
The roof mounted equipment HV busbars have been re-instated; connecting the pantograph, overhaul Vacuum Circuit Breaker and new HV Cable Assembly.
A set of new brake blocks have been manufactured and fitted to the locomotive. The hydraulic Parking Brake system has been serviced and re-commissioned. The Brake Hoses and Buffer Beam mounted brake cocks have been replaced.
Following completion of external repairs to the cab roof domes the cab ceiling and ceiling installation has been reinstated. The cab interior panelling has been refitted and the cab interior lighting has been re-commissioned.
The Cab Doors have been fitted with new seals and the flooring has been reinstated.
The windscreen wiper and wash systems at both ends have been re-commissioned with new motors, arm and blade assemblies being fitted in addition to new filling piping being fitted in the cabs when the washer bottles were installed.
Plans have been made for repainting and live testing if the locomotive, these stages are now on hold until after the Covid19 virus outbreak has passed.
Picture; (Left-Right) Installing new Surge Suppression Capacitors, Rebuild Rheostatic Brake Stacks awaiting installation, #2 end of the locomotive with roof removed – modified Choke cover (red) fitted, central section of locomotive showing rear of Control Cubicle and location for Surge Suppression Network, #2 Field Convertor Cabinet, Armature Convertor Covers and Air Handling equipment reinstated, #2 Brake Stack viewed from roof, Field Battery being installed, Field Battery Compartment after cleaning and repainting, Field Convertor status display during testing.