Wednesday, 1 May 2013

Steel Keel For A Wherry.

At the WYCCT yard at Wroxham on March 5th 2013 "White Moth" was hauled onto the slipway to have her wooden keel replaced with one of steel.  The wherry yacht "White Moth" was built by Ernest Collins in 1915.  King George V ruled Britain and the commonwealth and Henry Asquith was Prime minister.  Since then, to the best of my knowledge, "White Moth's" wooden keel has survived three monarchs, twenty seven Premierships and two World wars. 

When I was first told "White Moth" was having her wooden keel replaced with steel I thought it would make some interesting film footage - I never realised just how interesting this rare piece of engineering would be.  Having spent thirty years in the aviation industry I am no stranger to the many problems that can present themselves during heavy maintenance.  Remarkably this tricky project worked like clockwork from start to finish as each stage was meticulously planned and executed.

"White Moth's" keel clear of the slipway
The first step was to carefully raise and support "White Moth" clear of the slipway.
Then the old keel was surveyed and measured to ensure the steel replacement would retain the same amount of draught.  The old keel bolts were located and exposed by chiseling away sections of keel allowing the bolts to be cut through.

Profiles were fitted to the thirty two feet, or so, of keel on both port and starboard surfaces.  Then using the profiles as a pattern, shallow rebates were sawn along the entire length of the old keel with an electric saw, forming a guide for the serious surgery that was about to follow. 

The keel undergoing serious surgery

A two - man saw of an undetermined vintage was brought into the daylight for, what I imagine was,  the first time for many moons.  It was akin to the type of saws that were once used in saw pits.   Starting at the stern, the two-man saw began slicing its way efficiently through "White Moth's" ancient wooden keel.   The relentless effort needed to drive the saw through six inches of close grained Pitch Pine was nothing short of hard labour.  In spite of the frequent breaks required in the interests of rest and recuperation the keel was cut through surprisingly quickly.

One half of the two man saw in action

After cutting through the keel only a combination of clamps and wedges held it in place. As the clamps were slackened off  the wooden keel was dropped neatly alongside the slipway track, precisely where  intended.  It was difficult to estimate the exact weight of the old keel, but thirty odd feet of Pitch Pine in free fall could not underestimated.  With this in mind great care was taken to ensure that when the keel fell it did not disturb any of the props supporting "White Moth".  The plan worked perfectly. 

Wooden keel removed
While the old keel was being removed it's metal replacement was being fabricated in the "wet shed".  From there it was suspended by an ingenious arrangement of block and tackle and conveyed over the water.  Finely balanced and resting uneasily on a dinghy the new keel was eventually aligned with the slipway where it was submerged onto the slipway track.  

New keel crossing the water
Accompanied by the familiar sound of the ratchet rattling over the cogs on the winch "White Moth's"  new keel, shark-like in appearance, emerged from the water.  Gradually it was winched up the slipway into position beneath the Wherry yacht.

The new keel was winched up the slipway

The keel was temporarily jacked into position to allow the new keel bolts to be aligned with the fixing points inside the hull and the corresponding points on the keel. 

Keel bolts aligned
Nuts were welded to the upper surface of the metal keel and the keel bolts were turned into them with mole grips.   Everything was now aligned and ready for the keel to be raised and secured to the hull.

Nuts welded to the new keel.
A liberal application of Sikaflex marine sealant was applied to the keel's upper surface to form a watertight seal.  Finally the new keel was jacked into position and bolted down inside the hull.
Job done!

Job done!

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