I met Ian Welch several years ago, owner of Ab663. At that time he told me that they had fitted the drivers of this engine with Timken roller bearings, and that a standard size had been used for this job.

Mr Welch gave me a copy of "Mainline Steam Trusts Preserved Steam Locomotives" by Graeme E Moffatt, which contains a pretty good write up of this engines' in service history and her restoration. It also mentions the roller bearings on the engine and tender bogies, but NOT the drivers....

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1994 accident Edit
In 1994, during the first run of a preserved steam locomotive from Edinburgh to Newcastle, 60532 suffered extensive damage during a catastrophic uncontrolled wheelslip.

During an unscheduled stop at Durham station the inexperienced footplate crew overfilled the boiler. As the train departed south across Durham viaduct an initial slip was poorly controlled by the driver, who then reopened the regulator too early, probably worried about stalling on the bank up to Relly Mill. The force of the initial slip caused the boiler to prime, carrying water over into the regulator valve and jamming it open. This allowed passage of steam through to the cylinders, perpetuating the slip and accelerating the driving wheels. When the driver attempted to wind the reversing gear back into mid-position to halt the slip, the force of the motion spun it into full-forward position, and the driving wheels reached a rotational speed of 140 miles per hour before the cylinder heads blew off and the motion disintegrated.

The driver suffered major injury to his arms, as a result of the screw reversing lever whipping around when he released it. The accident brought to light the importance of train crews being trained on the specific locomotives they were driving, rather than simply a common general instruction on steam locomotives. Neither the driver or fireman had ever worked 60532 before, and were unaware of the locomotive's sensitivity to priming, which led to the accident.

The loco in the video is Ab663 built in Addington (Christchurch) New Zealand in about 1917.

It has plain bearings on the drivers.

The incident happened last weekend in the Plimmerton yard of Main Line Steam just minutes after the loco had returned from a 200 mile main line excursion. Had the excursion train been heading the further 15 miles south to the capital city of Wellington, the incident would have happened while running at 40 mph along side the bay.

Fortunately, in this case, due to the ever restrictive rules on steam locomotives passing through tunnels in New Zealand, the excursion terminated at the village of Plimmerton which is now Main Line Steam's main base after loosing their Auckland facility to housing development earlier this year.

The incident was caused by lack of lubrication of the bearing journals.

Trevor Heath
Casa Grande, Arizona