Ortho Photos – Massive Detail

Ortho what?

With the 3D model built, it is possible to create a single, massive scaled and GPS referenced 2D image of the site – an ortho photo. In the case of the SS Thistlegorm we have 5:

  • The overall 5 acre site ‘divers eye’ view – each pixel represents 10mm of area.
  • Deck 1 holds 1, 2 & 3 – each pixel represents 1mm of area.
  • Deck 2 holds 1 and 2 – each pixel represent 1mm of area.
  • The Rope Room under the forecastle – each pixel represents 1mm of area.
  • The Captains Quarters under the bridge – each pixel represent 1mm of area.

Here’s an example. The ortho photo of holds 1 and 2, deck 2:

This image is scaled down to view online. The original image, scaled at 1mm per pixel, is 2.68Gb in size. You can count the treads in the motorcycle tyres, if you want – the level of detail is that good.

Here’s a view of deck 1, holds 1, 2 & 3:

Just like the main site, the holds and rooms surveyed are geo referenced. However, it makes sense to rotate them to fit the page, rather than leave them orientated with respect to north.

Only by using an ortho photo can we ever expect to see this view of the cargo holds. Its worth remembering that both decks have a ceiling above them, often with less than 1m between the cargo and steel ribs.


Here’s another example:

The wreck is laid out and orientated correctly with due north at the top of the image. The background of this image is an Admiralty chart dated 1872 and revised in 1948. This was the closest example of a chart carried by the Thistlegorm at the time of her loss…and the wreck is actually marked on the 1948 edition.

Prints and Jigsaws

Jigsaws, Fine Art Prints and Posters of the SS Thistlegorm are available to purchase online here Deep3D store

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