Talk:Titan (submersible)

Safety factor = 1

Any engineering student can calculate in 5 minutes: Compressive stress in the carbon fiber polymer (CFRP) wall of the Titan submersible was about 200 newtons per millimeter squared at Titanic depth. This corresponds to the stress level where CFRP typically fails under compression. Only under tensile load (which is not applicable underwater), CFRP can withstand about 10 times more. What's more, OceanGate used unidirectional (circumferential) CFRP. This means that in the longitudinal direction, the hull was only about half as strong, at around 100 newtons per millimeter squared. It's a miracle the ship even made it to Titanic a few times without imploding. DavidGPeters (talk) 17:47, 28 June 2023 (UTC)

The 2017 CompositesWorld article noted the CFRP cylinder was laid up in two orthogonal directions (axial and circumferential in alternating layers), but that one (built by Spencer) was damaged by testing and replaced by another (Electroimpact/Janicki) in 2020/21, of which we know relatively little regarding its construction. The investigation is likely to provide more illumination, so we have to be patient for that to proceed, as otherwise we'd be lapsing into original research / speculation. Cheers, Mliu92 (talk) 17:56, 28 June 2023 (UTC)

Here is a video showing that the cylinder is being wound only in the circumferential direction: youtu.be/Vi4J1LDS504?t=10 DavidGPeters (talk) 20:47, 28 June 2023 (UTC)

Also, the thin-walled cylinder stress calculation would not hold here, as r/t is greater less than 10. Cheers, Mliu92 (talk) 17:59, 28 June 2023 (UTC)

This is not a special thin-walled cylinder stress calculation, but a simple force equilibrium of the absolute water pressure in relation to the cross-sectional area of the cylinder wall. Edit: I see now what you mean. The calculation is still correct, approximately. More precisely calculated, the result can only get worse for the stability of the Titan sub. DavidGPeters (talk) 21:04, 28 June 2023 (UTC)

The "5 minutes calculation" doesn't take in account, that load is transferred from the CFRP structure to other parts of the hull. Helmigo (talk) 12:33, 16 August 2023 (UTC)

Titanic tourism section

Most that that should be in OceanGate Titanic Expedition (draft started at DRAFT: OceanGate Titanic Expedition) instead of in this sub article, as it concerns the operations of the tour, and not the operations of the sub. Mission specialist and prices are something about the tour and not the sub. -- 64.229.90.172 (talk) 21:22, 28 June 2023 (UTC)

Since the submarine sank on one of these expeditions and they were the purpose for which it was built, I think there's a solid argument that the information belongs here as well. --Licks-rocks (talk) 21:28, 28 June 2023 (UTC)

Hey that draft has a lot of really good information. I think it should be added to the existing Titanic tourism section of this article. If the section becomes very long we can always discuss spinning it off into another article, but for now I don't see a need. Anybar (talk) 03:40, 29 June 2023 (UTC)

Titanic or the Titanic?

Titanic largely uses the former, Wreck of the Titanic (a GA) largely uses the latter. Other article titles use the latter (here, here, here, here) and vary within the body itself. Anyone know an actual rule about this? Pinging Cerebral726 since they reverted me. 199.208.172.35 (talk) 16:20, 29 June 2023 (UTC)

Ah, here we go: Wikipedia:Naming conventions (ships)#Using ship names in articles. No "the" is preferred. 199.208.172.35 (talk) 17:05, 29 June 2023 (UTC)

Thanks for looking into that. I wouldn't have expected that originally. Cerebral726 (talk) 17:58, 29 June 2023 (UTC)

MrBeast connection WP:INDISCRIMINATE

Is there consensus to include the fact MrBeast claims he was invited on the sub once but didn't go? It seems like we shouldn't be listing people who could have dived in the submersible. We don't even list people confirmed to have dived in the submersible. TulsaPoliticsFan (talk) 22:09, 29 June 2023 (UTC)

I agree it doesn't belong in the article. If it is true that this guy was invited on Titan once, I don't think it's important enough information to include in an encyclopedia article about this submersible per WP:INDISCRIMINATE Anybar (talk) 22:48, 29 June 2023 (UTC)

Similar discussion at Titan Submersible implosion TulsaPoliticsFan (talk) 22:48, 29 June 2023 (UTC)

I agree. It looks like more than one person turned down such a trip; unless they gave encyclopedia-worthy commentary as to why, it's probably not worth a mention here. 199.208.172.35 (talk) 13:58, 30 June 2023 (UTC)

The hatch

In the sub-section Features, the final paragraph talks about the hatch: “Once the occupants were aboard, the hatch was closed and bolted from the outside”. The section on Design and construction appears to say nothing about the hatch. For example, the second paragraph under Features says “The entire pressure vessel for the crew used five major components” but says nothing about the hatch.

The hatch for entry and exit of occupants was an essential part of the vehicle so the article should give some information about it. Dolphin (t) 03:22, 1 July 2023 (UTC)

The "hatch" is the entire end-cap. There is no separate hatch, you unbolt the entire end of the sub. The entire titanium hemisphere. -- 64.229.90.172 (talk) 22:48, 1 July 2023 (UTC)

This is a good start. Do we have a reliable published source that confirms your information? Dolphin (t) 06:17, 2 July 2023 (UTC)

Did you watch the David Pogue videos? Or any of the videos showing the operations of the sub? -- 64.229.90.172 (talk) 12:28, 2 July 2023 (UTC)

Unfortunately, no. Dolphin (t) 13:34, 2 July 2023 (UTC)

This source, already used in the arcticle says:"The crew will enter and exit Cyclops 2 through the front of the hull, which will be accessed via its hinged titanium end dome." and in the sketch it is mentioned that the Titanium End cap is hinged for crew entry and exit.Yeti-Hunter (talk) 07:44, 7 July 2023 (UTC)

Yeti-Hunter Thank you for your information about Sloan as a suitable source. I have amended the second paragraph under “Features” by inserting this sentence: The forward hemispherical end cap could be detached from its interface ring, becoming a hatch that allowed crew members to enter the crew compartment before a mission, and exit at its conclusion. Dolphin (t) 11:36, 7 July 2023 (UTC)

References

Infobox image

Strugglehouse, you likely weren't aware of this, but the 3D model was removed by Cerebral726 based on the discussion linked in their summary, then re-added later on, further down the page, by an IP. Not sure if either of you (or the IP) feel strongly about whether it should be included or not, but I figured I'd at least open a discussion. 199.208.172.35 (talk) 16:29, 3 July 2023 (UTC)

to be clear: the issue is that there are currently no open source images of the submersible as far as we've been able to tell. One user made a 3D render, which is what was reinserted. Several users rejected this version as it lacked some key features. Personally I think it's better than nothing as long as we're clear about its shortcomings, but that's me¯\_(ツ)_/¯ --Licks-rocks (talk) 16:50, 3 July 2023 (UTC)

This would be the logical place to use a non-free image, but I have almost no experience in that area, so I'm not sure if we've justified the use of one yet (see relevant discussion at accident article). 199.208.172.35 (talk) 17:10, 3 July 2023 (UTC)

@199.208.172.35 No, I don't mind at all about the image. I just moved it into the infobox because I felt it fit better there than underneath the infobox. It can be deleted or kept, I am not fussed. Strugglehouse (talk) 17:38, 3 July 2023 (UTC)

• The image is not accurate and several editors oppose its use on Wikipedia. See discussion at Talk:Titan_submersible_implosion#Infobox_image TarkusAB^talk/contrib 19:15, 3 July 2023 (UTC)

More of a mess - Knightoftheswords281 uploaded a non-free image for use here, but it was replaced by the 3D render again by Iruka13. 199.208.172.35 (talk) 19:01, 10 July 2023 (UTC)

More details

Composites World has an article about the Cyclops 2 [1] which goes into detail about the construction specifics of the Spencer Composites tube, including what kind of carbon fibre, the prepreg, the epoxy, the curing process, etc ; since we are already using this source, we could expand on the construction of the sub -- 67.70.25.80 (talk) 23:39, 12 July 2023 (UTC)

Basic design

The mating of a hemisphere to a tube when both are in compression results in a shearing force at the interface. The hemisphere loads are radially outwards. The tube loads are radially inwards. The loads are opposite. Glue in shearing mode was used together with a small lip. Has this been discussed? 2A00:23C6:F680:2C01:6CAB:85C1:7C84:95FB (talk) 09:12, 20 July 2023 (UTC)

The loading on the hemisphere is radially inwards, like a self-supporting architectural arch, but at the outer rim of the hemisphere there are forces acting in a way that tries to spread the rim (increase the diameter of the rim). Although some WP:Editors will understand the concept of rimming and splaying open the diameter of an opening, many won't understand the complexities of your contribution due to a lack of comprehension. I understand what you're saying, and I agree with you. The asymmetric loadings will tend to cause rimming and suck off the tube, eventually leading to the contents of the tube being ejaculated into the ocean. 2A00:23EE:1508:2376:D33:38A4:8C3:FA82 (talk) 21:15, 21 July 2023 (UTC)

After a little more thought it seems to me that as the tube compressed on earlier dives the flat ends of it would try to open like a book from the mating face with the hemisphere flange , starting at the outside. Even a tiny failure would allow water into the carbon matrix. 2A00:23C6:F680:2C01:6CAB:85C1:7C84:95FB (talk) 14:47, 30 July 2023 (UTC)

Composit hull replaced in 2021?

The article says: "After testing with dives to its maximum intended depth in 2018 and 2019, the original composite hull of Titan developed fatigue damage and was replaced by 2021." But the reference says: "During 2020 and 2021, the Titan’s hull was either repaired or rebuilt..." Helmigo (talk) 10:24, 6 August 2023 (UTC)

Semi-protected edit request on 19 August 2023

Change

In an interview published in 2020 with Teledyne Marine, a subsea technology company, it was noted that many Oceangate employees were recent graduates. To this, Rush responded that he "wanted [his] team to be younger, be inspirational" instead of including "ex-military submariners," who he described as "a whole bunch of 50-year-old white guys" like other submarine enterprises.

to

In an interview published in 2020 with Teledyne Marine, a subsea technology company, it was noted that many Oceangate employees were recent graduates. Rush responded that he, unlike other submarine enterprises, "wanted [his] team to be younger, be inspirational" instead of including "ex-military submariners," who he described as "a whole bunch of 50-year-old white guys". Course material reduce (talk) 13:46, 19 August 2023 (UTC)

 Done Lightoil (talk) 04:51, 20 August 2023 (UTC)