Thread by @RSA_Observer

The alleged transcript of communications between the Titan and the Polar Prince prior to the Titan's implosion. The transcript shows that Titan struggled for twenty minutes to return to the surface before finally imploding.

Early in the news cycle relating to the Titan submersible disaster, there was a note around a message having been sent from the Titan to the Polar Prince (the surface vessel) about problems being experienced by the Titan.

The content of that message and its significance never became apparent during the news cycle.

Now there is an alleged transcript of the communications between the Titan and the Polar Prince. The transcript has not yet been verified but reading it,...

it has the ring of authenticity to it and it seems to 'fit' with what we know. Also, the deepwater submersible community is a small tight community and it is quite conceivable that the transcript may have been exchanged within the community and leaked from there.

Here's a brief outline and analysis of the alleged transcript (link at the end).

Titan starts its dive just before 8 AM.

Every 15 minutes the Polar Prince messages the Titan and requests status updates.

Based upon publicly available information, Titan should have taken about 2 ½ hours to descend to the Titanic at 3800 m. That means Titan should descend at just over 25 m per minute or 380 m every 15 minutes.

But 15 minutes into the dive Titan says she is at 756 m. That means that she is descending at very nearly twice the normal speed. All systems are normal.

At 45 minutes, she is 1934 m. At her normal rate of descent Titan should have been at only 1140 m.

At an hour and 15 minutes into the dive she is at nearly 3000 m. But everything is still stable. Polar Prince raises a concern about the rate of descent questioning whether the velocity of descent should be reduced.

Titan reports that everything is under control and that no adjustment is needed to the rate of descent. The time is now just after 9:19 AM.

Less than 10 minutes later at 3433 m – nearly at Titanic depth – Titan reports that her real-time monitoring system is giving an alarm.

The real-time monitoring system comprises acoustic sensors on or in Titan's carbon fibre hull which are intended to detect if the hull starts to experience undue stress.

OceanGate had made much of this real-time monitoring system as a safety feature that would enable any problems to be identified early in the dive and to permit the safe return to surface of Titan should the carbon fibre hull started to fail.

Titan reports that she is going to reduce her rate of descent. However, it becomes apparent that Titan is having difficulty reversing the direction of travel. At 9:30 AM she reports that despite using her thrusters, the rate of descent is increasing.

Titan says that she is going to release her ballast. At 9:32 AM Titan reports that there is no improvement in the situation despite apparently dropping her ballast. Titan next reports that she is going to attempt to jettison her landing frame (the square structure underneath).

Titan is following a three-stage emergency procedure to reverse her descent. Dropping the landing frame is (in all likelihood) the last option Titan has for improving her buoyancy.

At 9:35 AM Titan reports that after multiple attempts she has managed to jettison the frame.

Three minutes later at 9:38 AM, Titan reports crackling sounds coming from the rear of the submersible. At 9:42 AM she says that the sounds have subsided, but all her hull health real-time monitoring are red.

About a minute later Titan reports that she is ascending but that the ascent is very slow and the reason for this is not clear (it is probably because Titan has started taking on water – see further below).

Titan is now at 3476 m. This is still 43 m *deeper* than when she first started to detect a problem.

At 9:46 AM, about three minutes later, Titan has risen slightly to 3457 m. This is still just a little bit more than 20 m *deeper* than when the problem was first detected.

Titan is clearly struggling to ascend.

Polar Prince requests a status update from Titan and asks what the wattage is on the upward thrusters. Titan reports that there are more sounds coming from the rear of the vessel.

Titan also reports that she is 'reading red' on 'A power bus' and that she was switching to 'B'. The bus reference is to a node for reading power. This indicates that Titan probably had a failure on her primary power system and had switched to using her backup system.

Titan's power systems are in the rear part of the submersible within the titanium dome that is attached to the back end of the carbon fibre hull, and the area from which the crew had been hearing the cracking sounds. This is the last communication from Titan.

A simple analysis tells us that Titan probably experience something not all that different to USS Thresher, U.S. Navy submarine that sank during a dive on 10 April 1963. The theory is that some silver braised joints on USS Thresher's sea water piping started failing.

Then the seawater started to affect Thresher's electrical and electronic systems, the result being that she started to take on yet more water and could not establish positive buoyancy, so that in the end she was driven deeper until she imploded.

Taking the various elements we can surmise that in all probability as Titan's hull came under pressure and started to fail, she may have started taking water on board in the rear area where her electrics and electronics were located.

This may have ended her communications with the surface. We don't know yet what then happened. But possibly as water entered her, she would have slowly started to sink deeper and finally imploded.

The earliest verifiable appearance of the transcript is on paste bin on 29 June: .pastebin.com/8g5mzTh0

PS: Apologies. Brazed joints. A braised joint is only useful in the cook's domain on a submarine.