What is most puzzling is we had access to U-209 blue print (which is considered one of best post cold war diesel submarine designs) and could have continued building it and improving on it.
I read somewhere that the front hull shape / dynamics is patented by HDW and we cant copy it.
The Germans apparently trained us well, and we had good know-how in basic design of hull (lt., beam, calculations, etc.) and also welding, inspection and QA (dunno wat it means in this case), trim calculations, battery tech , sea testing, maintenance and overhaul. Ulrich Gabler personally trained the Submarine Design Group.
But no voice in India was heard demanding the following:
1. We will carefully preserve and continue the hard won know-how from Germany .
2. We will build 3 more local follow on subs with knowledge received, with a slightly different hull form designed by our people in NSTL, which wont get us in trouble legally.
3. Engines will be from Kirloskar (license MAN). Battery from Exide (lic. Varta) , prop shaft and block from HEC, Ranchi. it will not be perfect but we will use it. We understand that it will be noiser than the Type 209, and quieter than the Foxtrot flogged till 2006. This is a very acceptable trade off for us. We also understand that as our people get more sophisticated, the next iteration of submarines will be equivalent to Type-209.
4. Motors, control valves castings and forgings will be from local industry (some Mumbai based MSMEs are very good with this stuff). Rubber anechoic tiles from MRF, periscope from DRDO-IRST, welding tech from ISRO - CMTI.
5. Hatches and bulkheads will be from Flash Forge, Vishakapatnam.
6. Sonar and CMS will be from BEL, Bangalore.
7. Torpedo will be from BDL, Vishakapatnam, a localised Russian TEST 65 with NATO dimensions and imported electronics.
8. We will have a continuous improvement program, where the designers will document improvements to be piped in for the next batch of vessels.
9. BHEL will source a casting for the propeller, and machine it to spec.
If someone had said something like the above, we would have had 75 % localised submarines, worst case !.
[The next iteration would have brought us close to 90 % +. ]
Wat actually happened was MDL master welders resigned and went to Gulf, to weld the oil pipelines and make good money.
Even now, seeing the Scorpene mishandling by MDL (MDL "procured" items to show phony indigenisation, for eg., and long delays in submarine commissioning, when using the latest concurrent engineering technology to save lead time), I have little faith in anyone achieving the same level of competence as in Type-209.
S. Korea took the same approach and succeeded with Chango-Bongo (whatever !), their version of Type-209.