Mosquito construction question

[Kutscha]

Molds were used for the fuselage but were they male or female molds?

[Graham Boak]

Male.

[Kutscha]

I ask Graham because of this



http://fennerschool-associated.anu.e.../Mosquito.html

[Graham Boak]

Good point! I understood that the plywood was formed over concrete formers, and had a photo in mind but didn't think I needed to search for it. That photograph suggests the upper part of a two-part mould. From the looks of your photo the shape may well have been made over a male mould, but then the two parts of the mould brought together to set the shape.

Clearly I do have to find something to justify my answer. There are photos of Mosquito fuselage production in Sharp/Bowyer's classic Mosquito from Faber, in Howe's Mosquito Portfolio (Ian Allan) and his The De Havilland Mosquito An Illustrated History Pt.1 (Aston) and Ian Thirsk's Pt.2 (Crecy). They all show male moulds for the half fuselages, held by steel bands while the wood sets under compression. The halves are then fitted out, and brought together, being held by wooden frames. No sign of any female moulds, or positioning holes for anything like the tool in your photo.

So your photo is not how the Mosquito was made - what make you think this was a Mosquito tool?

[Kutscha]

Maybe the photo is the plug for the mold.

[Graham Boak]

By "plug in the mould" I would normally understand the male part of a mould, so I don't get the meaning of your comment. It is clearly one part of a two-part mold, judging from the bolt fittings.

The photos I have show no place in the process for anything like that. Unless the manufacturing processes in Canada of Australia were completely different to those in the UK, which seems very unlikely.

If it is a Mosquito, could it be a mould for a fibreglass replica for a film? The view is perhaps foreshortened, but it doesn't look to be the right shape for a Mossie. It looks more like the mould for an underbelly fuel tank on a Meteor, or something similar. (No, I don't know how the Meteor belly tanks were made.)

[Kutscha]

A plug is the 'master' from which production molds are made from.

In fibre glass boat construction production molds have to be replaced every so often. Without a 'master' there would be variations in the production mold.

[Bruce Dennis]

[quote= Unless the manufacturing processes in Canada of Australia were completely different to those in the UK, which seems very unlikely.
[/quote]

..but very possible. Companies who were producing aircraft and aircraft components on contract were often entirely free to use their judgement as to how to achieve results, and this continued to be so until the technology and litigation of the 1970's forced the issue. In the 1930's-40's woodworking techniques in particular were varied as firms new to aircraft production were employed, often reflecting the machinery or experiences of a particular firms prior products.

When the all-ply fuselage of the Lockheed Vega was made, everyone available in the factory was called to 'grab a handfull' and wrestle, as a team, the sheets of wood into shape on the formers, with some men running full speed into the backs of the men holding the wood to gain the last few inches of movement for the wood to snap into place. (I'm not making this up). If their efforts to secure larger contracts had succeded, the management had accepted that they would have to find somebody who could show them how it should be done. It would not surprise me at all to find that a firm with experience of mass producing boat hulls for example would be given the contract for Mossie fuselage and wing components precisely because they knew a better way to achieve results.

Bruce

[Graham Boak]

Master I understand, but would that rate of wear be true for concrete moulds? However, it makes more sense, and something like that would be necessary to establish production in the first place.

I'm not completely convinced, because it lacks all the intermediate bulkheads and hence openings in the moulds as shown. You couldn't cast a concrete part from that, and then cut into it to make the bulkheads. It might be possible to fit formers inside it, but then you have the problem of lifting a 50 ft concrete block, split into sections (or all too willing to split into sections), from the master and positioning it on the shopfloor. Moulding it in place would require boltholes in the floor, and I don't see signs of them. But then maybe the lower fitting was removable after pouring?

Maybe.

[Kutscha]

Found this link on Mossie construction in Downsview.

http://www.virtualmuseum.ca/pm.php?i...00000192&pos=1