18th century hovercraft?

It would be hard to detail here all of the many, many ideas we have had, some good, some bad, in answer to the technical challenges of lifting the boat and removing it from the cellar. The team at MNH includes Steve Blackford, Head of Properties and his colleagues, and, very importantly, the Technicians, led by Geoff Mitchell. So much thought has gone into our plans that we often forget how we got here. One of our contractors asked this week "Why can't you just take the boat apart and re-assemble it somewhere else?"


http://cureentnews.blogspot.com/2010_07_08_archive.html



It's a perfectly reasonable question, after all. The answer is that we are trying as hard as we can to preserve what we'd call Peggy's 'archaeological integrity' - that is, all of the tiny relationships between every tiny element she's made of. We know she's a very significant boat but we don't know everything about her, so we are trying to keep as much of the evidence as possible. However carefully we tried, taking her apart would damage her a lot, and that would defeat the point of moving her.

Lately Geoff and I have been thinking hard about the way that Peggy, in her steel support cradle, will slide out of the boat cellar. We are shortly going to lay rails on the cellar floor that'll eventually lead out of the door and into the yard. We have to try to get the rails precisely aligned with each other and on the correct slope. There'll be three rails including one in the centre under the keel. Geoff has designed Teflon pads that the cradle will sit on to help it slide down the rails. Now, obviously we don't want that to happen too soon (!) because the boat will be sitting still for a year or so while we prepare the site for her exit. The pads are not so slippery, nor the slope so steep, that the boat won't stay put. How then to get it moving when the time comes without causing it to judder and shake?
Geoff has invented an ingenious solution to this problem. Each Teflon pad will be fitted with a compressed air inlet. The underside will have grooves in it that will let the compressed air escape, very much like a hovercraft but without the rubber skirt. We calculate this will provide just enough lift to get the boat moving down the rails. Turning off the air supply will act as a brake. Rest assured we will film the device in action so you can see it.

Installation date fixed

The news this week is that I have now fixed a date in the middle of June for the lifting of the boat and the installation of the new support cradle. On the Isle of Man it's usually a good idea to avoid programming complicated site work during the TT Festival in May/ June, so as to avoid getting in the way of the many visitors who visit the Island at that time to enjoy the fun and thrills!

Hydra-Capsule Ltd, of Bishops' Frome, Worcestershire will be lifting the boat for us; they are bridge lifting specialists but have lifted boats before, too. The cradle itself will be delivered in bits, by crane, into the the yard outsides the cellar. It'd be a lot easier if the yard weren't completely walled-in... 

 

Nautical Museum Basement level Ground Plan by APA Architects



Then it's simply a matter of inserting the 8 metre central keel support (by hand) and assembling the arms and ribs. The foam inserts that are designed to fit snugly between the steel ribs and the hull are now on order from Polyformes Ltd of Leighton Buzzard.

Meanwhile, I am getting quotes in for the removal of the bank in the foreground of the photograph (see my previous post dated 4th March 2013).

ICON Positive Futures 2013

No post this week as I have been attending the Institute for Conservation Triennial Conference in Glasgow:

ICON Conference logo

It was a very stimulating two days and a chance to meet a lot of friends, old and new. Story telling and engagement with colleagues, friends and the public was a strong theme - keep watching this space!

The new cradle takes shape

The fabrication of the new cradle for Peggy has been a complicated job, with a good deal of discussion and refinement along the way. In this photo, Kevin from Galla's Foundry in Douglas checks the profiles for the ribs that will eventually support the boat.

... and in this one you can see the lifting superstructure that will protect and support the boat when eventually we lift her out of the boat cellar by crane.