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Introduction
Waiting for repairs
Fixing the electrics
Making contacts
Beside the seaside
The Salvage Squad's first view of the tram is when it is stuck at the back of a disused bus depot in St Helens, Lancashire.They have five months to get it gliding along the Blackpool promenade once more.
Tram car No 304 was delivered to Blackpool in June 1952. It was the first of a batch of single deck trams that the corporation bought after the end of the Second World War. These vehicles represented a considerable development of the British tram. Technologically advanced, they incorporated Variable Automatic Multinotch Braking and Acceleration Control (VAMBAC) and rubber sandwiched wheel sets. As far as comfort was concerned, they were considered to be the most luxurious rail coaches ever built.
They were still being delivered in 1953, when Elizabeth II came to the throne, so Blackpool Corporation called them Coronation Cars.
The tram that the Squad are working on had remained in service until 1970. Then it was stored, waiting for someone to come along and restore it.
Fifteen years later, tram enthusiast Philip Higgs bought the tram using the proceeds from a book he had written when he was still a schoolboy, about the history of the Blackpool tramway. Philip started work on the restoration with volunteers from the Lancastrian Transport Trust but progress was very slow.
The tram is one of the biggest challenges the Salvage Squad have faced. Jerry takes on the task of restoring the complex and troublesome VAMBAC unit. Claire works on the trolley pole and tower, and the interior details, while Axel concentrates on the bodywork and the tram's electric motors.
The four motors need to be totally refurbished and Axel gets expert help from Dave Hesketh at Bowers Electricals.
An electric motor is quite simple: the electricity enters at the back via small carbon blocks called the 'brush gear', which rub on contacts around the central axle. The electricity then energises dozens of powerful electromagnets in the central part of the motor called the armature. These electromagnets then spin within a second set of magnets that are contained within the main casing of the motor.
The first step is to withdraw the armature from the body of the motor and then remove the brush gear. Axel next has to wash the body and armature to remove dirt and carbon from the electrical coils. After that, he puts the cleaned armature into an oven to dry.
Axel then takes on a machining task, putting the armature on the lathe to 'skim' the commutator (a cylindrical assembly of insulated conductors connected to the coils on the armature). He has to shave off a tiny amount of copper to ensure a good contact then file out the gaps between each of the 200-odd contacts by hand. He then assembles the brush gear with new springs and carbon brushes.
After fitting all the parts back together Axel and Dave run the motor up to speed on the bench, using a tachometer to measure the rate of revolution of the armature shaft. It runs perfectly.
When the Squad see the tram cruising smoothly up Blackpool prom on a beautiful sunny day, they can imagine how exciting it must have felt to have a day at the seaside in those early days after the Second World War.
Steam plough | Crane | Morgan | Tram | Steam car | Loco | Dustcart | Fireboat | Gallopers | Watermill
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