Shawn C has commented on Malaysian and mainly Singapore navy issues below – including Singapore’s Invincible class (Type 218SG) submarines might sport a mix of 533mm and 650mm torpedo tubes. Comments in square brackets [...] by Pete.:
Drawing from Shawn C’s comments 1.on May 24, 2020 and 2.on May 25, 2020
1.Frankly speaking - Malaysia is too much of a close economic partner with Singapore and I don't think they are seen as strategic competitors, especially in terms of defense. The last decade has widened the gulf between the military capabilities of the two, and niggling border [maritime, water and aviation] issues aside, Malaysia benefits from a neighbour who is willing to help them in terms of data fusion and ISR, particularly around the Malacca Straits and parts of the SES[?]. [See this December 2018 Youtube Video on maritime dispute].
That is not to say that Singapore doesn't ignore any Malaysian 'posturing'. There's plenty of stories by Singaporean National Servicemen of some of the 'mobilization exercises' they've gone through.
https://www.straitstimes.com/singapore/saf-holds-largest-mobilisation-exercise-since-1985-with-8000-troops-700-vehicles
Singapore is a signatory of the NPT and does not have a nuclear industry - also no place to put a nuclear plant with a 30km safety zone.
It's a certainty that Singaporean and Israeli submariners have 'bumped into' each other during the construction of their respective submarines at TKMS, but what systems are shared is of course conjecture at this time, and I don't think the Israelis would let sailors of other nations into their super-secret subs. More likely the Singaporean crewmen trained on Type 212 boats.
We know from launch images of the RSS Invincible/Type 218SG [and see Wiki link] that while the sub has a family resemblance to the Dolphin II, the sail is located centrally, there are four X- rudders instead of the seven (four rudders and three fins) on the Dolphin II, and a broader keel that runs almost the whole length of the submarine.
What wasn't shown in the images, was the Invincible's eight torpedo tubes, and it may be that, like the Type 212, they have an asymmetrical torpedo tube layout, and could even be a mix of 533mm and 650mm tubes [like the Dolphin 1s and 2s!], which would make a lot of sense for special forces and UUV use, amongst other things.
Did TKMS torpedo Kockum with Australia and Singapore? The Swedes think so.
https://www.thelocal.de/20131015/52407
Ultimately Kockums was removed from the SEA 1000 project because "they hadn't built a submarine in twenty years". In a What If scenario - TKMS-Kockums get awarded the A26 project in 2010, and in 2012, with some delays, cuts steel on the first boat. In 2013 Singapore signs in for a customised version, so Kockums now has a 4 submarine order book. This keeps them in the SEA 1000 downselect.
https://au.finance.yahoo.com/news/sweden-barred-australia-sub-program-105608893.html
2. [Pete never mentioned any Scorpenes had AIP. Only the 3 DCNS (now Naval Group) designed Pakistani Navy Agosta-90Bs have DCNS MESMA AIP. It was Wikipedia that wrongly implied MESMA AIP on Scorpenes hereand in Wikipedia’s right sidebar].
You might be interested that the Republic of Singapore Navy (RSN) trains in the Andaman Islands with the Indian Navy https://www.straitstimes.com/singapore/a-rare-look-at-rsn-submarine-training-crew-can-now-take-out-adversary-within-minutes
The Chief Trainer of Submarine Forces RSN, is a Perisher graduate:
https://www.straitstimes.com/singapore/why-whiskey-was-the-last-thing-on-rsn-submarine-commanders-mind-during-gruelling-perisher
Checked up on the Polish A17 story, and I think there's a lot of unsubstantiated conjecture in the article, specifically with Sweden 'buying back' the Archer class submarines in 2023.
https://www.defence24.com/is-sweden-willing-to-maintain-its-submarines-and-their-potential
The RSN currently operates two Challenger class and two Archer class subs. The Challenger boats are over fifty years old [originally launched in 1968 and 1969] and in RSNcommission for twenty years, so their replacement by the first pair of Invincibles is urgent. With the Archers its a little more complicated - they were extensively modernised over five years and have been in service for about 9 years, which means they should be able to remain in RSN commission till 2030 without any major life-extensions needed.
While most commentators see the RSN'sintent is to replace the Archer's with the second pair of Invincibles, this won't happen till the boats are delivered in 2024-2025 (not 2023). The RSN may also be planning to expand its submarine forces to six submarines, and keep the Archers in commission while ordering a third pair of [Invincible class] Type 218SG boats for delivery later in the decade.