high-pressure superheated steam boilers

General naval discussions that don't fit within any specific time period or cover several issues.
adrian6045
Junior Member
Posts: 7
Joined: Thu May 24, 2012 12:45 pm

high-pressure superheated steam boilers

Postby adrian6045 » Mon May 28, 2012 8:23 am

What alternatives were there for the German navy to the use of high-pressure superheated steam boilers in their ships prior to world war 2, could diesels have been a credible alternative.

User avatar
RF
Senior Member
Posts: 7488
Joined: Wed Sep 20, 2006 1:15 pm
Location: Wolverhampton, ENGLAND

Re: high-pressure superheated steam boilers

Postby RF » Wed May 30, 2012 6:48 pm

Diesels were a credible alternative BUT the timescale in developing the very large diesels to drive a Bismarck was too long for the immediate requirements of German planning 1934 onwards. Turbines were used for the Scharnhorsts and Bismarcks because they were more immediately available.
''Give me a Ping and one Ping only'' - Sean Connery.

Paul L
Senior Member
Posts: 300
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: high-pressure superheated steam boilers

Postby Paul L » Tue Jul 16, 2013 8:08 am

The Germans were toying with large diesels in WW-I BB.


All 5 Kaiser class were fitted for a Diesel in the center shaft, while 2 of the 4 Konig class and all of the Bayern class each had a single large diesel on center shaft.

This was a huge diesel engine with 12000 hp @ 150 rpm and could manage 12 knots. The late 1920s diesels on the PBS were 4 x 12,000 hp @ 250 rpm. These were smaller engines and its reasonable to think a BB sized diesel by 1930s could have reached 20,000 hp each. With three shafts ; 6 linked diesels generating 120,000 hp diesel, could get ~30 knots for a Scharnhorst sized warship with a smaller bunkerage plus endurance in the 10,000/20knts region.
"Eine mal is kein mal"

User avatar
RF
Senior Member
Posts: 7488
Joined: Wed Sep 20, 2006 1:15 pm
Location: Wolverhampton, ENGLAND

Re: high-pressure superheated steam boilers

Postby RF » Wed Jul 17, 2013 7:14 pm

This last post is interesting. Given the diesel technology used for the panzerschiffe I was always puzzled about the next class of ship, the Scharnhorsts, weren't made diesel powered with the next generation of large diesel engines - instead the Germans went back to turbines.
''Give me a Ping and one Ping only'' - Sean Connery.

Paul L
Senior Member
Posts: 300
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: high-pressure superheated steam boilers

Postby Paul L » Thu Jul 18, 2013 5:36 am

Well its my understanding that the original 1932 plan for Panzerschiffe D&E was for a 15-18,000 ton super cruiser with 3 triple 11" guns and diesel or turbine propulsion with Graf Spee armor. Initially 74,000hp could be managed by diesel ; while turbine in the same hull would be 86,000hp .Endurance was hoped to be 6700nm @ 20 knots. When Hitler took over power; the designs evolved rapidly to Scharnhorst, with 18 steps along the way [22-25-26-30kt models were all examined]. The only way to keep 30knots possible when that design exceeded 30,000 tons was to use high pressure turbines. Raeder took a risk that the new high pressure turbines would not only deliver the hp but also the fuel economy needed. No one spoke of reliability.

Considering his idea for the use of Panzerschiffe was for them to operate oceans away, the Diesel or at least a Diesel turbine comb should have been more appealing . So I suppose he should have abandoned risk of high pressure temp turbine engines for proven reliability of diesel/turbo combo?
"Eine mal is kein mal"

User avatar
tommy303
Senior Member
Posts: 1526
Joined: Mon Oct 18, 2004 4:19 pm
Location: Arizona
Contact:

Re: high-pressure superheated steam boilers

Postby tommy303 » Fri Jul 19, 2013 7:39 pm

This last post is interesting. Given the diesel technology used for the panzerschiffe I was always puzzled about the next class of ship, the Scharnhorsts, weren't made diesel powered with the next generation of large diesel engines - instead the Germans went back to turbines.


The problem was the next generation of diesels were not ready yet and would not be for a sufficiently long length of time to drastically delay the building time table. Unlike turbines and boilers, which can wait to be installed after a hull has already reached an advanced state of construction, diesel engines of the time needed to be completed and ready for installation very early in a hulls construction since their bedding was much more extensive and the engines needed to be installed and aligned before construction of the rest of the hull proceeded. From that point on, the hull was quite literally built around the engines.

Their shoulders held the sky suspended;
They stood and Earth's foundations stay;
What God abandoned these defended;
And saved the sum of things for pay.

Matrose71
Member
Posts: 62
Joined: Mon Feb 08, 2010 2:46 pm

Re: high-pressure superheated steam boilers

Postby Matrose71 » Sat Jul 20, 2013 2:28 am

tommy303 wrote:
This last post is interesting. Given the diesel technology used for the panzerschiffe I was always puzzled about the next class of ship, the Scharnhorsts, weren't made diesel powered with the next generation of large diesel engines - instead the Germans went back to turbines.


The problem was the next generation of diesels were not ready yet and would not be for a sufficiently long length of time to drastically delay the building time table. Unlike turbines and boilers, which can wait to be installed after a hull has already reached an advanced state of construction, diesel engines of the time needed to be completed and ready for installation very early in a hulls construction since their bedding was much more extensive and the engines needed to be installed and aligned before construction of the rest of the hull proceeded. From that point on, the hull was quite literally built around the engines.


I have read this too at the Navweaps forum, but I have serious doubts about this issue from a technical viewpoint!

From all I have read in several books and some MAN sources, all MAN two stroke double-acting Diesels, M8Z 30/44 (Bremse), M7Z 30/34 (Leipzig), M9Z 42/58 (Deutschland class), M9Z 65/95 (H-class), later M12Z 42/58 (without auxiliary engine, with a added purge air box) and the whole VZ12 family (V12Z 42/58 and V12Z 32/44 also with a added purge air box), had no fundaments or beddings. They were completely built with tie anchors and without a baseplate. The crank shaft was "free in the air" only covered from a steel sheet box.
I can't see why you can't install engines with tie anchors later in a ship hull, because you are only in need to install the tie anchors.
Do you have material/photos or sources for your opinion?

To my sources and books the traditionalist at the K-Amt came out on top at the planing of the Panzischiffe D and E and the new destroyers, and at the end of 1933 the development money for MAN diesel engines was shortened about 80% and switched to the developer of steam turbines and especially the development companys for the high pressure steam boilers.
Also through the time with massively shortened development money MAN could develop and deliver till 1938 the M9Z 65/95 (H-class) and the M12Z 42/58 (without auxiliary engine, with an added purge air box) . The M9Z 65/95 is an enlarged PBB engine with the disadvantage that one engine has the weight of 225ts and was in need of an auxiliary engine. The MI for the H Class was about 5200 ts compare to 2700ts of BS with steam turbines. The M12Z 42/58 (without auxiliary engine, with a added purge air box) was the first innovation (1935/36) because it wasn't in need of any auxiliary engine.

The real brake through came 1938, after the development money for MAN diesel engines was massively increased through the many problems with the high pressure steam turbines (SH/GS and all destroyers), with the construction and building of the V12Z 42/58 and V12Z 32/44 with an added purge air box.
This were two stroke double-acting 24 cylinder V engines
The VZ12Z 42/58 runs first time on a test stand 1939 and the V12Z 32/44 1940.

For comparison.


V12Z 42/58; 15.600 PSe continuous ; 8,75 power/weight ratio kg/PS; 136,5ts weight; built 1
V12Z 32/44; 10000 PSe continuous (12.500 continuous turbo charged); 5,10 power/weight ratio kg/PS; 50,8ts (60ts turbo charged) built 4, one you can see at the Museum at Sinsheim.
M9Z 65/95; 15.000 PSe continuous ; 15,00 power/weight ratio kg/PS; 225ts weight (built 6-8)

To my opinion the K-Amt gave away near 4 years of development time with the decision to change horses at 1933, we don't know when the VZ12 family could be ready, if the K-Amt hadn't changed horses and had supported fully MAN, but to my estimation at the end of 1936 the VZ12 family could be ready, especially V12Z 32/44. The true innovation was 1936 with the added purge air box, which makes the auxiliary engine unnecessary, the rest is engine development from known engines.

Paul L
Senior Member
Posts: 300
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: high-pressure superheated steam boilers

Postby Paul L » Sat Jul 20, 2013 3:11 am

Matrose71 wrote:
tommy303 wrote:
This last post is interesting. Given the diesel technology used for the panzerschiffe I was always puzzled about the next class of ship, the Scharnhorsts, weren't made diesel powered with the next generation of large diesel engines - instead the Germans went back to turbines.


The problem was the next generation of diesels were not ready yet and would not be for a sufficiently long length of time to drastically delay the building time table. Unlike turbines and boilers, which can wait to be installed after a hull has already reached an advanced state of construction, diesel engines of the time needed to be completed and ready for installation very early in a hulls construction since their bedding was much more extensive and the engines needed to be installed and aligned before construction of the rest of the hull proceeded. From that point on, the hull was quite literally built around the engines.


I have read this too at the Navweaps forum, but I have serious doubts about this issue from a technical viewpoint!

From all I have read in several books and some MAN sources, all MAN two stroke double-acting Diesels, M8Z 30/44 (Bremse), M7Z 30/34 (Leipzig), M9Z 42/58 (Deutschland class), M9Z 65/95 (H-class), later M12Z 42/58 (without auxiliary engine, with a added purge air box) and the whole VZ12 family (V12Z 42/58 and V12Z 32/44 also with a added purge air box), had no fundaments or beddings. They were completely built with tie anchors and without a baseplate. The crank shaft was "free in the air" only covered from a steel sheet box.
I can't see why you can't install engines with tie anchors later in a ship hull, because you are only in need to install the tie anchors.
Do you have material/photos or sources for your opinion?

To my sources and books the traditionalist at the K-Amt came out on top at the planing of the Panzischiffe D and E and the new destroyers, and at the end of 1933 the development money for MAN diesel engines was shortened about 80% and switched to the developer of steam turbines and especially the development companys for the high pressure steam boilers.
Also through the time with massively shortened development money MAN could develop and deliver till 1938 the M9Z 65/95 (H-class) and the M12Z 42/58 (without auxiliary engine, with an added purge air box) . The M9Z 65/95 is an enlarged PBB engine with the disadvantage that one engine has the weight of 225ts and was in need of an auxiliary engine. The MI for the H Class was about 5200 ts compare to 2700ts of BS with steam turbines. The M12Z 42/58 (without auxiliary engine, with a added purge air box) was the first innovation (1935/36) because it wasn't in need of any auxiliary engine.

The real brake through came 1938, after the development money for MAN diesel engines was massively increased through the many problems with the high pressure steam turbines (SH/GS and all destroyers), with the construction and building of the V12Z 42/58 and V12Z 32/44 with an added purge air box.
This were two stroke double-acting 24 cylinder V engines
The VZ12Z 42/58 runs first time on a test stand 1939 and the V12Z 32/44 1940.

For comparison.


V12Z 42/58; 15.600 PSe continuous ; 8,75 power/weight ratio kg/PS; 136,5ts weight; built 1
V12Z 32/44; 10000 PSe continuous (12.500 continuous turbo charged); 5,10 power/weight ratio kg/PS; 50,8ts (60ts turbo charged) built 4, one you can see at the Museum at Sinsheim.
M9Z 65/95; 15.000 PSe continuous ; 15,00 power/weight ratio kg/PS; 225ts weight (built 6-8)

To my opinion the K-Amt gave away near 4 years of development time with the decision to change horses at 1933, we don't know when the VZ12 family could be ready, if the K-Amt hadn't changed horses and had supported fully MAN, but to my estimation at the end of 1936 the VZ12 family could be ready, especially V12Z 32/44. The true innovation was 1936 with the added purge air box, which makes the auxiliary engine unnecessary, the rest is engine development from known engines.




This is very interesting information "Matrosse71". It does seem to confirm my suspicions.

Is there any source you can supply that covers this information on Diesel development?
"Eine mal is kein mal"

Matrose71
Member
Posts: 62
Joined: Mon Feb 08, 2010 2:46 pm

Re: high-pressure superheated steam boilers

Postby Matrose71 » Sat Jul 20, 2013 4:27 am

Hello Paul L,

my sources to the MAN Diesel are all in german:

Source: Werner F.G. Stehr, »Unbekannter Motor für KM-Kreuzer wiederentdeckt«, in: Marine-Arsenal Special Band 3, Podzun-Pallas 1995

This source gives the complete development history of the MAN diesel engines till the VZ12 family, with year of development, test stand runs, performances, technical layouts etc.

Source: Hans Georg Prager ,Panzerschiff Deutschland, Schwerer Kreuzer Lützow

At this source are detailed infos about the technical installment of the Panzerschiff engines and the engines of the training ship Bremse with many drawings.

From our german forum, Marinearchiv, several Members have visited the historical Archiv from MAN and had the permission to read many primary sources about the MAN diesel engines. From there we have the informations about the shortened development money at 1933 and the massively increased development money at 1938.

Also I have several books with seperated chapters about the development of the MAN diesel with technical description and performance specifications and I was at the Museum of Sinsheim and have seen the original V12Z 32/44.

Note: My writing about MAN diesel engines in this thread, is explicit to large MAN diesel engines, which were able to power large surface war ships, this excludes the development of submarine engines.

Matrose71
Member
Posts: 62
Joined: Mon Feb 08, 2010 2:46 pm

Re: high-pressure superheated steam boilers

Postby Matrose71 » Sat Jul 20, 2013 4:54 pm

Unlike turbines and boilers, which can wait to be installed after a hull has already reached an advanced state of construction, diesel engines of the time needed to be completed and ready for installation very early in a hulls construction since their bedding was much more extensive and the engines needed to be installed and aligned before construction of the rest of the hull proceeded. From that point on, the hull was quite literally built around the engines.


Also what contradict this thesis is the history of Z 51, which was launched autumn 1944 and was fitted out till it's bombing end of march 1945 and till this time no VZ12Z diesel engine was installed. And to all sources Z 51 should get the VZ12Z 33/44 as propulsion system.
Three shafts with 6 x engines, each outer shaft one engine and 4 engines on the center shaft.

Paul L
Senior Member
Posts: 300
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: high-pressure superheated steam boilers

Postby Paul L » Sat Jul 20, 2013 7:15 pm

Thanks for the sources Matrose71

It is my understanding that when a ship is launched it is traditionally launched complete with its entire propulsion system. This is why its very expensive to replace one propulsion system with another since you have to cut the boat open in the hull area or into sections to extract and replace these systems. Parts of the system my be removed but not the bulk of it.

Auxiliary propulsion systems may well be added later along with the entire electrical wiring system.
"Eine mal is kein mal"

sineatimorar
Member
Posts: 176
Joined: Fri Jan 18, 2013 1:42 pm

Re: high-pressure superheated steam boilers

Postby sineatimorar » Fri Nov 22, 2013 12:24 am

A couple of points I would like to have clarified.
1./ although designed to have diesels the WW1 ships never had them fitted as although designed and a prototype was constructed, no production model was constructed as the prototype exploded while completing endurance run killing a number of engineers as I recall.
2./ From what I was able to reseach the V24 motors designed by MAN where all medium speed 4 strokes and not double-acting slow speed diesels.
3./ Diesel engines were only considered in the improved armoured cruiser design that was superseded by the design that was to end up as the Gs and Sc. Initially I thought that turbo-electric power was the initial type for this and the next class?

As far as I know the only battleship designed to be fitted with diesels was the H39.

Matrose71
Member
Posts: 62
Joined: Mon Feb 08, 2010 2:46 pm

Re: high-pressure superheated steam boilers

Postby Matrose71 » Mon Dec 02, 2013 10:11 am

2./ From what I was able to reseach the V24 motors designed by MAN where all medium speed 4 strokes and not double-acting slow speed diesels.


All VZ12Z engines V 24 cylinder were double acting 2 stroke engines, same as the MZ family from the Panzerschiffe and the training ship Bremse.
Rpm was 390 U/min for continuous power and 400 U/min (Panzerschiffe M9Z 42/58 ) for high performance, so this isn't a slow speed diesel, it is a medium speed diesel.

Next to the H-Class, the Schlachtkreuzer O and the P-Class were planed with diesel engines on the outer shafts.
Also Z51 was built with only diesel engines.

3./ Diesel engines were only considered in the improved armoured cruiser design that was superseded by the design that was to end up as the Gs and Sc. Initially I thought that turbo-electric power was the initial type for this and the next class?


Only at BS and TP were existing plans about a turbo-electric power, it was considered as a to heavy power plant.


Return to “Naval History in General”

Who is online

Users browsing this forum: No registered users and 2 guests