Two questions

[Rainerle]

Hi I have two questions for any history buffs out there.

1.) Why are there no australian and/or new zealandian submarines ??

2.) What class were the 4 Siames (Thai) submarines delivered by japan ?

[Skyland]

Hi,
For the question 2, it was Sinsamut Class. I don't know if it was based on actual japan sub class.

http://www.navy.mi.th/nrdo/Chakri/king8.htm#8

H.T.M.S. SINSAMUT
H.T.M.S. PHLAI-CHUMPHON
H.T.M.S. WIRUN
H.T.M.S. MATCHANU

[el cid again]

This class was offered for sale by Mitsubishi. It did not win any sales to any service other than RTN, but could have been built by IJN or a number of other navies. I considered building them for IJN in EEO - which indeed does build additional submarines before WWII. Ultimately I selected a different class of larger boats - but with the same main weapons. These were model for Japan's very best submarines of the main war period - which differed by the addition of oxygen generating equipment for Long Lance torpedoes. The earlier submarine designe - including the RTN one - could not use the long lance - and do not in RHS. [There is a special 21 inch version of Long Lance just for submarine use.]

[Dixie]

The Australian/New Zealand question may be because pre-WW2 the RAN & RNZN (and the RCN) were intended to operate as part of the RN during operations.  This was a fairly common view with regard to the Commonwealth armed forces before (and during) the war.
I may well be wrong so don't think it is a definate answer, but I am fairly sure that this is a major part of the thinking.

[el cid again]

Submarines were regarded as essentially defensive platforms in pre war thinking - with notable exceptions. [Adm Donitz was all alone in believeing in medium sized medium range seagoing submarines for offensive operations - the minimum package so maximum numbers could be fielded - and the numbers he felt were required never were achieved. USN and IJN - and experimentally other navies with one off's like Surcouf - had a concept of "fleet submarines" of long range and high speed operating with the fleet - ideas that never worked out very well due to communications and speed issues.] Anyway - most navies regarded submarines as defensive platforms - something which also did not work out very well - the Dutch probably coming closest to being effective in NEI operations. Australia and New Zealand hoped not to fight in home waters, and focused on cruisers for offensive work, depending on escort vessels and minesweepers for local operations or distant ones - as might be required. This was supplimented by a number of coast defense batteries - and these are remarkable for how few and light they were. No one really expected much worse than WWI type German landing parties off merchant ships and raiders in PTO. [That is what Marine Defense Battalions were intended to fight - never mind it never was a threat in WWII] Most British submairne designs were small and medium - and not ideal for PTO operations - and few were in PTO when war erupted there - even in RN. These were focused on defense of India - not on waging offensive war in Japanese home waters (like USN attempted from the start).

[mlees]

The most likely source of submarine designs for those two nations (Australia and New Zealand) would be British designs (as those two nations would be expected to cooperate with the RN, and spare parts from the USA might not be forthcoming, depending on political circumstances).
 
The British sub designs were shorter ranged, as El Cid has said. They also lacked air-conditioning, at least in most of the prewar designs, IIRC. Sub duty in the tropics (Singapore, DEI, Solomons) is much more arduous without AC, and fatigues the crew faster.
 
British subs never-the-less operated some in the straits of Malacca and S. China Sea, but land based airpower made those areas pretty risky to be in (and they are pretty shallow, too).
 
The British lost a bunch of subs in the Med...

[JeffroK]

The RAN had 2 subs in WW1, one was lost off Rabaul, the other in the Sea of Marmara (Turkey)

I think the RAN had to spend its pennies wisely and with the tooing and froing about the legality of subs in post WW1 conferences decided to go with a small surface fleet. Also as part of the RN it would be assumed that the Brits would supply BB's, Subs & Carriers.

Also, the Dominions, Canada, New Zealand & Australia provided a lot of Officers and men for the RN so there was an investment made there rather than in equipment

[Rainerle]

Wow, thanks for all the info and the link even if my thailandese is lacking [:D]
Additional question: Does it work to put depth charges on planes for special ASW aircraft?

[m10bob]

ORIGINAL: Rainerle

Wow, thanks for all the info and the link even if my thailandese is lacking [:D]
Additional question: Does it work to put depth charges on planes for special ASW aircraft?

Yes, but I cannot tell you if the charges are anymore effective than bombs because when the plane attacks, it only sez "is attacking I-XX".

[Rainerle]

ORIGINAL: m10bob

ORIGINAL: Rainerle

Wow, thanks for all the info and the link even if my thailandese is lacking [:D]
Additional question: Does it work to put depth charges on planes for special ASW aircraft?

Yes, but I cannot tell you if the charges are anymore effective than bombs because when the plane attacks, it only sez "is attacking I-XX".

Thanks for the reply. To elaborate even further, do cannons alone work as ASW weapon?

[el cid again]

ORIGINAL: Rainerle

Wow, thanks for all the info and the link even if my thailandese is lacking [:D]
Additional question: Does it work to put depth charges on planes for special ASW aircraft?

It appears that DC and bombs are both rated in pounds, and code treats them the same, by weight.
RHS even has a 60 kg combination bomb/DC - it depends on the target what it is - but it represents both -
because device wise it is the same.

[el cid again]

ORIGINAL: Rainerle

ORIGINAL: m10bob

ORIGINAL: Rainerle

Wow, thanks for all the info and the link even if my thailandese is lacking [:D]
Additional question: Does it work to put depth charges on planes for special ASW aircraft?

Yes, but I cannot tell you if the charges are anymore effective than bombs because when the plane attacks, it only sez "is attacking I-XX".

Thanks for the reply. To elaborate even further, do cannons alone work as ASW weapon?

I hope so. RHS has ASW rockets - which are cannon with an ROF = 1 - and we hope they work as well. Apparently so.