Turbine engines

Clipped
"In an old electrical engineering textbook (dated 1929) that I have at home there is a description of the Steam Turbine/Electrical drive systems for USN Capital ships.
I've looked up the list of these ships, as follows :-

BB-40 New Mexico
BB-43 Tennessee
BB-44 California
BB-45 Colorado
BB-46 Maryland
BB-48 West Virginia
CV-2 Lexington
CV-3 Saratoga" End Clip

The Lexington and Saratoga were originally going to be built as battle cruisers but the Washington Naval Treaty resulted in their conversion to aircraft carriers. As battle cruisers they were to be armed with eight 16 inch guns, but originally retained eight 8 inch guns in four turrets (two forward and two aft of the island). In March 1942 the turrets were removed in favor of additional antiaircraft armament.

USMA74 wrote:Clipped
"In an old electrical engineering textbook (dated 1929) that I have at home there is a description of the Steam Turbine/Electrical drive systems for USN Capital ships.
I've looked up the list of these ships, as follows :-

BB-40 New Mexico
BB-43 Tennessee
BB-44 California
BB-45 Colorado
BB-46 Maryland
BB-48 West Virginia
CV-2 Lexington
CV-3 Saratoga" End Clip

The Lexington and Saratoga were originally going to be built as battle cruisers but the Washington Naval Treaty resulted in their conversion to aircraft carriers. As battle cruisers they were to be armed with eight 16 inch guns, but originally retained eight 8 inch guns in four turrets (two forward and two aft of the island). In March 1942 the turrets were removed in favor of additional antiaircraft armament.

IIRC Lexington still had her 8in guns when she was sunk at Coral Sea. Saratoga got hers changed to 5in/38 in March, which delayed her for Midway. IIRC Saratoga arrived at Pearl Harbor on June 7, the day the battle ended. Imagine what would've happened if Saratoga had joined with Yorktown and the USN had four carriers at Midway instead of three.

saber964 wrote:

IIRC Lexington still had her 8in guns when she was sunk at Coral Sea. Saratoga got hers changed to 5in/38 in March, which delayed her for Midway. IIRC Saratoga arrived at Pearl Harbor on June 7, the day the battle ended. Imagine what would've happened if Saratoga had joined with Yorktown and the USN had four carriers at Midway instead of three.

The four 8-in mounts were removed from Lexington at Pearl Harbor on 30 March 1942, and made available to the Hawaiian Department, U.S. Army, four days later. It was planned to replace the 8-inch/55 batteries with 5-inch/38 dual-purpose twin mounts, but Lexington was sunk on 8 May 1942, during the Battle of the Coral Sea, before the 5-in mounts were installed.

Captain Igloo wrote:

saber964 wrote:

IIRC Lexington still had her 8in guns when she was sunk at Coral Sea. Saratoga got hers changed to 5in/38 in March, which delayed her for Midway. IIRC Saratoga arrived at Pearl Harbor on June 7, the day the battle ended. Imagine what would've happened if Saratoga had joined with Yorktown and the USN had four carriers at Midway instead of three.

The four 8-in mounts were removed from Lexington at Pearl Harbor on 30 March 1942, and made available to the Hawaiian Department, U.S. Army, four days later. It was planned to replace the 8-inch/55 batteries with 5-inch/38 dual-purpose twin mounts, but Lexington was sunk on 8 May 1942, during the Battle of the Coral Sea, before the 5-in mounts were installed.

Yes, I checked my references and Lexington had 7 1.1 in batteries in stead as a stop gap measure.

Hears a fun one what if the IJN had been delayed say a week and Saratoga had been added to the USN's OrBat TF 16 and 17 with four carriers. FYI IIRC Saratoga was equipped with TBF Avenger torpedo bombers instead of TBD Devistators. Saratoga sailed into Pearl Harbor on June 7 the day the battle officially ended.

saber964 wrote:Hears a fun one what if the IJN had been delayed say a week and Saratoga had been added to the USN's OrBat TF 16 and 17 with four carriers. FYI IIRC Saratoga was equipped with TBF Avenger torpedo bombers instead of TBD Devistators. Saratoga sailed into Pearl Harbor on June 7 the day the battle officially ended.

Probably not too different, honestly. Maybe if the americans get lucky Yorktown makes it out, but they already had plenty of planes. Their problem was *using* them effectively - they had a bad habit of being uncoordinated and cut up piecemeal, not finding their targets, missing their targets, or having their torpedoes not function. Heck, they had an entire carrier's flight group - Hornet's - who only had one squadron find the enemy at all, and that to absolutely no effect.

Toss in Saratoga and maybe you get all 4 carriers in the first attack, but honestly only if you get lucky. And if you don't get Hiryu in that attack, she still gets off the two attack waves that leave Yorktown dead in the water for I-168 to sink. At which point the end results of the battle are pretty much the same.

PeterZ wrote:I thought Howsmyn used steam turbines for his industrial air compressors?

Hmmm...

Electrical power transmission ==> Pneumatic power transmission.

+

Reduction and other direct gear-age ==> Electrical generator/motor sets.

+

Naval engineering.

Result:

Turbine driven Pneumatic compressors driving pneumatic motor propulsion. Flexible power plant placement. Improved efficiency and control.

Could be a winner...

Max

Max wrote:Turbine driven Pneumatic compressors driving pneumatic motor propulsion. Flexible power plant placement. Improved efficiency and control.

Hydraulics rather than Pneumatics; possibly using seawater as a working fluid as suggested up-thread.

Pneumatic systems don't work well at low RPMs, but Hydraulics do. A turbine driven hydraulic pump could apply Hydraulic pressure to propeller pods, rudders, and transverse propulsion for close maneuvering.

Weird Harold wrote:
Hydraulics rather than Pneumatics; possibly using seawater as a working fluid as suggested up-thread.

Pneumatic systems don't work well at low RPMs, but Hydraulics do. A turbine driven hydraulic pump could apply Hydraulic pressure to propeller pods, rudders, and transverse propulsion for close maneuvering.

Umm... Pneumatic systems are already in-story, hydraulics are not. Pneumatic motors could easily be piston driven rather than turbines. Low to moderate RPM. Much like steam except you do not get the power loss over distance that you would get with steam. Further advantage is that it's an open system so you don't have the return piping problem with oil or the corrosion problem you would get with sea water...

While I am not a mechanical engineer, I can visualize a high volume turbine speed air compressor without fancy gearing. I have much more trouble getting the high speed of a steam turbine to run the low speed pumps of a hydraulic system without some pretty fancy gearing...

Max

Max wrote:Umm... Pneumatic systems are already in-story, hydraulics are not. ...

Hydraulics predate pneumatics in textev. It's a pre-Merlin technology, although Merlin did introduce accumulators.

Max wrote:While I am not a mechanical engineer, I can visualize a high volume turbine speed air compressor without fancy gearing. I have much more trouble getting the high speed of a steam turbine to run the low speed pumps of a hydraulic system without some pretty fancy gearing...

A high-RPM turbine driving a high-RPM pump can provide high pressure hydraulic fluid to a low-RPM motor -- or a very slow-moving actuator. The turbine + hydraulic pump is completely independent from the motors and actuators that use the pressure. In that respect, there is little difference between hydraulic and pneumatic systems. The main difference is in the compressibility of the working fluid.