Fenchurch's Boiler

Updated 14 August: old tubes being removed.

Fenchurch was taken out of service in 1988 for mechanical reasons, and although its boiler certificate had less than two years to run, the boiler itself was in good order. In 1975 its copper inner firebox had been condemned, and it had subsequently been fitted with a new steel inner firebox by a local engineering company.

A view of the boiler as it was after removal from the engine. The work done so far is the external surface has been cleaned and painted, and the regulator valve and its supporting elbow have been removed from the dome opening. The general condition of the boiler is good.

Work to be done

• Replace the tubes (life-expired)
• Replace the main steam pipe regulator elbow (corroded through the pipe, partly owing to poor casting)
• Replace the main steam pipe front elbow (flanges corroded away around bolt holes)
• Seal-weld the left firebox side-stays (see below)
• Seal-weld the palm-stay rivets on the bottom of the barrel
• Replace the smokebox (not expected to last another 10 years)

The main steam pipe internal elbow, showing how a combination of corrosion and a poor casting has resulted in a piece completely falling out. Stepney's elbow was replaced some years ago by a fabricated unit, but it is planned to make a casting for Fenchurch.

The main steam pipe external elbow, mounted on the front tubeplate inside the smokebox, showing how corrosion has eaten into the flange. This will be replaced with a new casting.

The Leaks

The only significant boiler problems which were encountered during its spell of operation in the 1980s were some fairly serious leaks from the firebox side-stays and the palm-stay rivets, and from the foundation ring seams. It is only in recent years that boilers have been steamed before fitting them into the engine frames. In Fenchurch's case, many of the leaks were in places which could not be reached with the engine fully assembled. Some of the stay leaks became sufficiently bad that the right tank was removed to get access to the stays, which were seal welded, as shown in the picture. During dismantling for its repair, when the boiler was unwrapped of its cladding the glass-fibre lagging material was found completely packed with lime-scale, which was firmly stuck to the boiler plates. Needle-guns were used to remove it, revealing the platework little harmed.

Work continues...

Removing the old tubes - boilersmith Andrew Wilkens drawing attention to the smokebox end of the tubes where he has been slitting them with the oxy-acetylene torch to release them from the tubeplate.

To be continued as work proceeds...

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