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[gondolier88]

WOW, thats the only word for that kind of model plant, the amount of hours put into that thing!!

My one and only criticism is that the engineering is first class, the layout spot in, but the plumbing is attrocious- such a shame to ruin a beautiful plant with plastic tubing, 'pigoen droppings' solder and fittings that are skewiff- if he re-piped it and took his time it would be far better in my eyes- not that I would say no if he offered me it

Greg

[Martin (Admin)]

Yes I noticed that Greg, 'hose-clips' etc but when asked Jack said it was a very much evolving engine and changing all the time, so when something finally worked properly and harmoniously with the rest of the plant, it was remade to a polished finish.

[SteamboatPhil]

Blimey--now having seen that little lot, I feel inclined to hang up my tools. 
really amazing work, how could you ever top that 

[Steamer]

Phil I know exactly the way you feel , I feel it too when I see a model like that or a musician playing and instrument like you and I breath, its very intimidating.  The mountain suddenly seems very big!

But I think thats a short sighted way to look at it really, we should enjoy the beauty and wisdom of a master and learn from what he or she is teaching us...

We should then just strive to be better.....

I think it took Karl a lifetime to combine the skills, experience and knowledge to create that master piece  ....We can not begrudge that.  .I suspect it will take us no less if that is vocation of choice for our hobby outlets, but look at the path already cut!   It's all there for consumption and study in photographic form.   We should take advantage of this as a learning opportunity.   "How did Karl do it?"

Dave

[Martin (Admin)]

I knew I had photos somewhere... actually taken by my mate John Bass.

[gondolier88]

Hi Martin,

You wouldn't happen to know why he used a fairly low speed mill engine using a gearbox with chains instead of just using a high speed vertical with direct drive 'a la originale'?

Greg

[SteamboatPhil]

Now I have seen Johns pics before, and I have to say with engines like those, why oh why did he use a standard ST diplacement lubricator, not sure he would have got enough oil into those triple expansion engines........ still nice expermintal work, which after all is what most of what we do is (my excuse--and sticking to it)
gonddolier--high speed engines (in small size) not as efficient geared as the triple is stand alone, I do say there is an awful lot of bits on there, which====== well we all have our own ways (but commercial plumbing fittings---after all that work------------yuk) Other than that, labour of love

[gondolier88]

Hi Phil,

I wasn't talking about the main engines, I was asking about the ST mill engine (No.9?) which has a chain driven gearbox running a 12V alternator- a much easier/efficient/lighter way of doing it would be to hook a Sirrius, or even a Cheddar Puffin with a double speed gearbox (much easier to engineer), with direct drive to the alternator shaft- all that chain and gears- non of it with tensioners on so will have so many loadings on it you won't believe- I bet he uses so much fuel it would scare a lesser man!

Greg

[ROSYTH]

Just thought i would pass on an email I received back from the Museum with regards to my initial enquiry on the builder of the Fantastic Steam Plant.

===========================================================

Dear Mr. Smith,
 
thank you for your query concerning one of our steam engines. It is the portside engine of one of Hapag's express liners named "Deutschland" (1900). The model was built in 1990 to 1995 by Karl-Friedrich Pohlmann, scale 1:20. It is a four cylinder compound engine with 17.000 PSi (indicated horse power).
Builders: A.G. Vulkan, Stettin; 16.502 BRT; Length 208,5 m; Width 20,5 m; 34.000 PSi; 22,5 knots; Crew: 557; Passengers: 429 I. Cl., 226 II. Cl., 284 III. Cl.

Yours sincerely
 
Dr. Axel Griessmer
Internationales Maritimes Museum
Peter Tamm sen. Stiftung
 

www.internationales-maritimes-museum.de
____________________________________
Vorsitzender des Vorstands: Prof. Peter Tamm (Vorsitzender), Lutz Erntges, Heiko Hermans, Prof. Dr. Hermann Schäfer Sitz Hamburg

And the Second reply back to that...................................

Dear Mr Smith,

yes, Mr. Pohlmann (aged about 80) is still with us and is working on the portside engine of R.M.S. "Titanic"! We have no catalogue concerning our house or literature concerning those modells. We only have them in our exhibition. Sorry for that. But please see the adress of Mr. Pohlmann. I think he will be very pleased if you contact him:

***Personal details removed by moderator***
I am sure this man has a lot valuables in his workshop.
If you wish to contact the gentleman concerned, please PM Rosyth for details.


Kindest regards
Dr. Axel Griessmer

So having that information I will shortly be writing to Mr.Pohlmann, yes WRITING as i suspect he doesn't do email and hopefully if he replies I hope he will include a few images of his latest project that will make up the pair of Steam Engines to complete his project.

Off course i will post any pics and reply he sends me and i hope to see more of his work in the near future.

Cheers
Rosyth

[Steamer]

Rosyth,

He did do email....unfortunately, that address died with my last PC......Please say hello for me!

Dave

[ROSYTH]

What a shame you lost his email............oh well back to pen and paper I guess but I will off course mention you in writing and the Forum too.

You never know he may just sign on as a member .

Cheers
Rosyth

[Steamer]

One could only hope!...

Here is one of the port engine of Titanic.



Dave

PS here is the back of the bottom picture


These engines are similar to the engines of a Liberty ship that controls the link position.

[Martin (Admin)]

What's this fitting / feature?

[Steamer]

Martin,
That would be the Thrust bearing assembly.   The brass tubes are for water cooling.

All propeller thrust is directed to those bearings( there are several lined up one behind the other).      That's what makes the ship move essentially

The pump in the foreground is the cooling water pump for the bearings.

Dave

[gondolier88]

Absolutely perfect!

Just wish we could see a bank of four boilers all linked up and steaming it!

Greg

[ROSYTH]

Now that would be a welcomed WISH indeed................1700psi full size.........it's a true monster of steam.

If only it could all be hooked up and run just once, filmed for all to see and archived with all us steam nuts........now i am dreaming but maybe I could suggest it
when i put something down on paper to our Mr.Pohlmann later this week

Can't wait to get his reply

cheers

[Martin (Admin)]

Ah! I see. Thanks for that... you can learn all sorts of stuff on here!
Next question what's the big worm gear set-up?

[gondolier88]

Hi Martin that's the 'barring' engine- because the engine only has one high pressure cylinder, if that cylinder was to be at either TDC or BDC then it wouldn't start- also on starting such a large engine it takes at least a couple of hours for it to warm through, before then the steam condenses in the cylinders.

The barring engine would move the flywheel around so the engine was moving already when steam was admitted- it would also be used to slowly rev the engine with a small amount of steam on to warm the cylinders through without putting any power to the shaft.

Greg

[oldiron]

  Steam turbines also use barring gears to turn the turbine over at slow speed when steam is shut off. This allows the turbine rotors to cool evenly and not hog. the same applies on startup. The turbine is put on barring gear well ahead of steam admission (several hours in many cases), this takes the droop, or sag out of the shaft to reduce vibration to within acceptable limits when steam is applied. When steam is admitted the turbine runs up and rolls off the barring or turning gear as rotor speed increases.
  Before starting turbines, even on barring gear, lubrication oil is forced into the bearings under pressure to lift the shaft on a film of oil. This is done with high pressure jacking pumps. The jacking pumps continue in operation until there is enough turbine shaft speed to form a reliable oil wedge between the shaft journal and the bearing. I would expect a large marine engine such as that pictured would have a similar arrangement.

John

[gondolier88]

Hi John,

Yes your correct, however due to a reciprocator not having anywhere near the same rev's it's nowhere near as complicated- although pressured oil systems were in use on relatively small plants, >30Hp, from around 1890, although typically it was just total loss some of the higher spec Belliss & Morcom, LIFU and Sissons engines employed pressured systems.

The pressure systems used the sump as a reservoir, pumping through a filter using a drive off the crankshaft- the most ingenious method was, I think, on a Belliss engine that had oil-ways in the shaf so oil was fed to one end, doing so lubricated the main bearings and the big ends- quite before it's time I think you'll agree.

Greg

[Steamer]

A very important use of the barring engine was for warm up.   As Greg pointed out, steam engines condense a great deal of steam during warm up.   Steam is compressable, condensed steam....otherwise known as water, is NOT compressable.   If the engine has a large sum of water in the cylinder when started , it will in all likelyhood break a cylinder head, piston rod or connecting rod when the piston comes up against the slug of water in the cylinder.

At warm up, some steam is bypassed around the thottle and feed to the engine, but with the cylinder drains open.   This is a small amount, and not enough to run the engine.   Then if the cylinders are steam jacketed, the jacket steam is started to warm the cylinders.   Not long after the the barring engine or turning engine as it is sometimes called is engaged, and it turns the main engine over slowly with the cylinder drain cocks open, distributing steam through the entire engine, instead of just where the steam can get to while the engine is stationary.   

Big engines like this would move around a great deal, and warming them was a laborius and time consuming operation, but absolutely necessary.


Once warmed, the turning engine was disengaged and the engine could be started as usual.


Dave

[Bunkerbarge]

Ah! I see. Thanks for that... you can learn all sorts of stuff on here!
Next question what's the big worm gear set-up?

It has a couple of other uses as well.  As has just been described prior to putting the engine on line you would turn the engine over with the barring gear (also nowadays known as simply turning gear) with the indicator or drain cocks open to prove the cyliners are clear of condensate prior to starting.  If this isn't done there is a potential danger of hydraulic locking, which can seriously damage running gear if you try to start the engine.  Turning gear is still used today on diesel engines and is still used to determine that the cylinders do not contain water from say a head joint, valve cooling jacket or injector cooling leak.

Another important use of the turning gear is when maintaining the engine.  The engine is regularly required to be turned during dismantling and reassembly of running gear and the engine is turned to the appropriate position to facilitate removing or replacing of fastenings.  Finally the turning gear is required when checking the timing of the engine.  Marks on the flywheel will align with a pointer on the entablature and will show the correct position of all pistons and valves to enable the timing to be checked.  Once again this is still used today to check the timing on diesel engines and the flywheel will be marked with top dead centre for each unit and an angular scale to enable you to determine when valves are opening and closing as well as when injection starts and stops.

[gondolier88]

You should see the barring gear on SY Gondola...it's a bar!!!! Takes some turning I can tell you!!

Greg

[Steamer]

Same thing on Sabino Greg,


Dave

[oldiron]

  In answer to Martin's earlier question about the thrust bearing on the Titanic engine. I thought he may like to get some idea of what the inside of a thrust bearing looks. I've included three shots to show the thrust surfaces on the crankshaft, the lower thrust half in place and finally , the upper thrust half installed. The brass box on top is for bearing oil and the worsted wool oil wicks.
  Granted this is a much smaller triple than the Titanic engine, but the principle is the same.

John