The Naiad Voyages

Mark Austen

2018.03.11 - Weigh Hey And Up She Rises

Having got Naiad into the workshop it was time to get everything off so that she can be inverted for the work under the waterline. This was a relatively simple task, in fact, it was harder finding places to store the boat contents, right up until the penultimate item, the centre plate. This weighs 30.5kg or 67lbs so it is difficult to get it out of the case in the cramped cabin. Still, taking it easy and using leather gloves to protect my hands I go it out safely.

I didn't move this too far away from the boat. It's heavy!

I've wondered ever since I completed the boat last year just how much she weighs. There are two main ways to weigh a boat with out taking it to the weigh bridge. The first one measures the weight of the boat only but requires moving the boat on the trailer back or forward by 12-18 inches and the second weighs the boat and trailer. I'm not able to move the boat on the trailer, so I used the second method.

Firstly the trailer is put on blocks so the the wheels are free to rotate with a third block under the tongue.

Then a lever is used to lift the trailer so that it is lifted off the block.

I used the chain hoist and an electronic scale to do the work with a pencil mark on the lever where it touches the trailer and also where the chain hoist is attached.

You can see here that the trailer is no longer resting on the block.

The load on the scale read 31.53kg.

The scale was also used to measure the downward force on the block at the front of the trailer. I couldn't get the exact measurement as the scale overloaded just as the trailer lifted, so I'll use 50kg here as this is the maximum that the scale will measure.

The lever measurements were 118mm and 1010mm.

Plugging these into the formulae gives an approximate weight of the boat and the trailer of 590kg I don't know how much the trailer weighs but it is probably about the same as the centre plate, mast and spars, so I'll say for now that the weight of the boat is probably no more than 600kg.

The quoted weight of the Fairey Falcon according to the manufacturer's data is 575 lbs all up, so the changes I have made have increased her weigh nearly two and a half times. Converting 600kg to imperial gives 1323lbs.

Compared to modern 16' dinghies, Naiad is staggeringly heavy. Nevertheless, she sails well.

An interesting afternoon!