P47-D Crash Site in Weymouth Bay. Now in 3D

It definitely dived in hard, characteristically after either a bale-out or pilot killed

We know the pilot lived. Portland War Diary records his rescue by a trawler.

The combination of high RPM and the high-speed impact have shattered it.

We have wondered if the prop had been snagged by a trawler or fishing gear, and ripped off the prop hub. But if we have some of the hub remaining, this discounts this theory. Thanks for the ID.

It is quite possible that the blades were cast far and wide upon impact.

We intend to extend the sonar survey, they still might just turn up.

Nice to see the fruits of modern technology being used on an aircraft wreck

Thank you – and yes please to your offer of technical data on the R-2800. Will PM you.

I get a ‘Forbidden’ message when I try to view the pictures – any idea why?

Mike – not sure why. I do block some russian IP address ranges to help prevent spammers constantly trying to hack the site. Were you accessing the page from home? Or work? What country are you in?

That’s fascinating, Simon.

It definitely dived in hard, characteristically after either a bale-out or pilot killed, as the propeller is shattered – and this takes some doing. The combination of high RPM and the high-speed impact have shattered it.

There is a small piece of the prop hub left on the drive shaft and the rest of it will lie about, probably submerged in the mud, though one or two of the u/i parts could be from it. It is quite possible that the blades were cast far and wide upon impact.

Corrosion is substantial, as might be expected, but more than would be the case with a relatively intact aircraft where sacrificial corrosion often leaves otherwise vulnerable parts in remarkably good condition for quite a while.

Nice to see the fruits of modern technology being used on an aircraft wreck.

I have some technical information on the R-2800 engine if you need it.

Anon.

I get a ‘Forbidden’ message when I try to view the pictures – any idea why?
Mike

Thank you. I now understand the principle. I think that I understand the detail!

But one question, please. Is the last image – the ortho photo – digitally enhanced? If not, then the waters of Weymouth Bay, at 25 metres down, are a lot clearer than when, in my youth, frequently I capsized in them whilst dinghy sailing!

The waters off Weymouth have not changed. Underwater visibility on the day was around 4~5m max, so there is no way the ortho photo could be taken in a single frame. The ortho photo is derived from the model and the 1100 or so individual frames, all stitched together and then presented as a single, scaled image. These ortho photo image files can be massive – 4~5Gb for a single image is not unusual, but the accuracy is often 1 pixel = 1mm.

This article discusses the volumes of data behind photogrammetry, including the ortho photos

Hope this helps?

Fascinating. I don’t pretend to understand the science but one can’t help but be impressed by what it is capable of producing. But one question, please. Is the last image – the ortho photo – digitally enhanced? If not, then the waters of Weymouth Bay, at 25 metres down, are a lot clearer than when, in my youth, frequently I capsized in them whilst dinghy sailing!

Nice work

Great pictures 🙂