[Ian6]

I sailed in several T2's, all turbo-electric. There were specific production issues as Cisco mentioned in the previous post (possibly related to General Electric getting the contract) but turbo-electic had some genuine advantages over straight steam turbine propulsion.

Steam turbines could not be reversed any more than a windmill can go backwards. The only options were to either fit expensive gearboxes or more usually a separate reverse turbine. This was much less powerful than the (usually) three stage forward turbine so an emergency stop didn't happen plus you didn't use reverse much but carried its weight around all the time. Turbo electric was also generally quieter and less prone to vibration, P&O fitted turbo electric drive to two of the 'Strath's prewar and the Canberra in 1960.

Any engineers reading this please excuse the layman's language I was only a navigator after all.

Ian

[Derek Roger]

Originally Posted by Cisco

Bob, all but a very small number of T2s were turbo-electric. I read once that this was chosen for them as the US didn't have sufficient gear cutting capacity for all the ships they were building in WW2 so naval ships , victorys, etc got the standard steam turbine kit. One company that liked turbo-electric was Union Steamship Coy of NZ. They used it on a number of their express passo boats.
They made handy power staions... T2's being used in Norway about 1960ish to supplement hydro power due to a drought and a few were also used in Vietnam during the war. At least one of the USS coy ships was also used in that matter after retirement.
I was on a Diesel Electric drill ship once, Glomar Grand Isle. When drilling the electricity went to the drill floor, when shifting ship someone threw a big switch somewhere and off we went. The 'telegraphs' were Baldwin locomotive controllers.......

Sailed the Glomar 2or perhaps 3 as 1St Engineer ( 2nd in UK terms ) from Aberdeen to North Shields in 72/73 ? Diesel electric DC . Generators used to drive the drill rig ; also when shifting the power was used for propulsion . She would not make any speed under her own power but when in tow the propulsion was used to assist which allowed a high speed tow .

[Stephen J. Card]

Originally Posted by Derek Roger

I have seen that done John ; a complete new hull onto an exsisting Engine room . What seems to being put forward here were convertions that would have had a new section to increase the lenght and some widening of the remainder of the hull to fair into the new section which was of 7 feet more in beam than the original vessel .
I can see how it could be done but would imagine that it would not be cost effective .

In the case of BANGKOK and SIAM... to take the afterpart of a 30,000 dwt tanker and attach it to a new forepart to increase capacity to 60,000 I would think that would be very cost effective. ie double the capacity but no new machinery.

[Derek Roger]

Originally Posted by Stephen J. Card

In the case of BANGKOK and SIAM... to take the afterpart of a 30,000 dwt tanker and attach it to a new forepart to increase capacity to 60,000 I would think that would be very cost effective. ie double the capacity but no new machinery.

I agree with that Stephen ; I believe that is what I said .. But to lenghten and widen an existing vessel does not to make sense re cost . I think that is what has been proposed and is being debated . Perhaps I have missed the reason for the post.

[Stephen J. Card]

Originally Posted by Derek Roger

I agree with that Stephen ; I believe that is what I said .. But to lenghten and widen an existing vessel does not to make sense re cost . I think that is what has been proposed and is being debated . Perhaps I have missed the reason for the post.

OK, let's talk a simple tank vessel. 1 centreline tank and sidetanks port and starboard. Dock the vessel, cut away PART of the sidetank which would include the vertical side plating, the bilge keel and the sheertrake. From what is left, extend the framing etc out to the new beam max and then plate up the sides, sheertrake and bilge keel. Cost probably not too bad and you might get another 10 to 20% capacity. No? Lengthening... that would be the easy way.

[chadburn]

Pre WW2 I think with GB shipowner's it was a matter of "the Devil you know" when it came to type's of propulsion. Crosswaites Tugs had a D/E tug built by Hall Russell in 1933 (the first in GB), the initial build cost was higher than the normal propulsion method's and she was certainly still with Crosswaites in the 1950's when I was at Smiths. Very much the American style of Tug she was the only one built for the Company.

[allanc]

A bit off topic, but as I recall, Normandy was turbo-electric.

[Bjorne]

during the winter 1061-61 there where 4 T-2 tankers in Sweden to supply electrical power. I was down in the engineroom of one of them ( Greek Owned laying just ooutside Stockholm) and it was spotles.