The Ship Model Forum

On Fusion360 you can create real gears of all kinds, there is an add-on for that. It's very easy to do.

But the system doesn't go down that low in size. So I have to make them myself.

Here is a seat belt arm gear from a recent Mercedes, designed and printed for a friend. He broke one.



The windlass is finished, all that remains is to print this series of parts.

I still have to draw a small crank winch, which is placed on the starboard side of the foredeck. And the aft compass.

The compass looks like this one:



Not easy to draw the anchor chain channels.

The short brass horns on either side of the binnacle were for some sort of illumination? The Red and Green "Navigators Balls" as we called them were in USN (now ancient) practice generally black. However on the ARL I followed LST practice in which the watch standers might have had trouble with left and right and painted them accordingly.

Ah Brasso, I still have a can somewhere, though you aren't supposed to use it on ammunition cartridge cases for reloading due to some change in properties it induces. It's always nice to be able to detail a bridge or pilot house, it's the brain stem of the ship. The large windows allow some visibility. Sometimes it's fun sometimes to just know it's there.

A lovely small project!

Kindest regards: Tom

We had a discussion about this in my WESPE-building log I think, but it seems that the compensation balls began to be painted in red and green respectively only in the 20th century. When on an open bridge, they were probably painted white to reduce their 'albedo', that is to increase their capacity to reflect sunlight so that they would not warm up and change the compensation settings.

The balls were used to compensate for declination, that is the horizontal deviation of the compass needle due to the iron masses on a ship. Inside the binnacle stand, there was another mechanism, invented by Lord Kelvin in the 1880s, I think, with weights that can be raised and lowered, to correct the ship's compass for inclination, that is the vertical deviation due to the iron masses of the ship.

Declination and inclination constantly change on a ship due to the redistribution of cargos, stores and other ferro-metallic items. Therefore, there was an area on many roadsteads on which ships could turn in a full cycle, while taking compass readings and compare them against a line of land-marks set up to indicate true North. The iron weights on the binnacle stand would be moved in and out and up and down to effect the compensation.

The two funnel-like objects next to the compass were indeed that, funnels for petroleum lamps that would be put inside the housings to illuminate the compass at night.

[quote="Fliger747"]The short brass horns on either side of the binnacle were for some sort of illumination? /quote]
Yes, I believe there were small oil lamps in these, lighting the compass rose from above.

The use of green and red for Stbd/Port respectively started only when ships' navigation lighting was introduced in 1848, when these colours really mattered. https://en.wikipedia.org/wiki/Navigation_light

Only after some time these colours were also used for other use on board, like on the compass compensation balls. The colours don't really have a purpose there, as Tom noted these could just as well remain black. In the Dutch navy (I think they copied that from the Germans btw) it was also common practice to paint the two anchor cable holders on the foc'sle red and green, so that might have been applicable to Hydrograaf too! In this case the faces of the two winch heads would receive the colours.

This practice was discontinued when the modern frigates (Kortenaer class) entered service around 1980, these ships having a single bow anchor and only one central cable holder.

For my part, on the many ships I have sailed on, I have always seen them painted black on the upper bridges, but there is no roule, i think, I have not known the wooden bridges and the compasses installed inside.
When installed on the upper bridge on a metal ship, a periscope installed on the bridge ceiling, with mirror, allows to check the course, especially against the 2 gyroscopes, every 4 hours.

As it is not watertight, water can fall on the bridge control console which is just below it in bad weather, so most of the time on ships, the compass is covered with a tarpaulin to avoid these leaks.

Compas periscope:

The setting procedure, performed after drydock generaly.

This gives a course deviation curve specific to that compass. This curve must be displayed on the bridge.

https://knowledgeofsea.com/magnetic-compass-correction/

Hi Pascal,

Maybe a bit late, but I would like to share a thought on the colour yellow you have used on the inside of the bulwarks. As the ship looks today, your paint choice matches perfectly. However, I'm inclined to think that in the past the yellow colour used on (Dutch) navy ships was not the golden rich yellow you have used, but a more white-ish yellow, also seen on utilitarian vessels like tugs and fishermen of the period.

To illustrate the point, included here two photos of Hr.Ms. Luymes A902 and Snellius A907, two of the last hydrographic vessels in the traditional colours. The yellow used on this is I believe a good example. Also this painting of Hydrograaf seems to point into that direction, even exaggerated, but that's of course subject to the interpretation of the artist: This picture of the even newer Buyskes, Blommendal and Tydeman illustrate the point even more: Humbrol 74 would have been a good choice, but you may be of course of different view.

Another point are the propeller shafts: as unpainted steel wil be very susceptible to corrosion, I think these are very rarely if ever left unpainted. Usually these have the same colour as the antifouling used on the ship's bottom.

But on shipyard presentation models it's a different matter, these were often adorned with much bling-bling that never was there on the real ship. If you want to capture that look your choice is very justified of course.

Well, I had the same thoughts as Maarten on both, the ochre and on the unpainted propeller shaft.

Confronted with the question of which ochre to choose in may current project, I did some research on the subject, as pictorial representations seem to vary from a rather pale beige-yellow (buff) to an almost orangy one, depending on the time and the navy. I had hoped to find some recipies for particular periods and navies. However, recipies seem to be often rather vague. In addition, the ochre used (either natural or synthetic towards the end of the 19th century) can vary dramatically from a pale yellow, through orange, to a blueish red. It depends on the mineralogy of the original material and its processing, but I don't want to bore you with the details. The ochre is but one ingredient. It is usually diluted with either lead-white or ground limestone (cheaper). The eventual hue will depend on the ratios between ochre and the white pigment, as well as the amount of line-seed oil and the purity of it.

It would be interesting to see, whether any recipes for the Dutch navy could be unearthened ...

Thanks Maarten,

It is a possibility for the yellow, in doubt I took the tone of the current yellow.
Your yellow is close to the yellow of the White Star Line in 1900s, called 358 light buff.

A color that evolved later.

http://www.titanic-cad-plans.com/whitestarbuff.pdf

When it comes to the external propeller shafts, for ships with two shaft lines, there are two systems, either the stainless shaft is surrounded by a steel tube filled with oil from the etambot, the rear bearing is then lubricated with oil, which is what we find today, or there is no protective tube and the stainless shaft is naked in the sea water, which can be found in the days of the Hydrograaf or Nomadic. In the first case the steel tube is protected by paint like the hull, in the second case the propeller shaft is not painted. About Hydrograaf, i don�t have any picture of the shafts, so i think is same system than Nomadic.

Actual marine stainless propeller shaft:

https://www.marineinsight.com/naval-arc ... struction/

https://en.m.wikipedia.org/wiki/Stainless_steel

However, at the time of HYDROGRAAF's construction, there would have not been any stainless steel around, at least not in these quantities and in a quality that could be forged and then turned to size.

Iceman 29 wrote: ... Your yellow is close to the yellow of the White Star Line in 1900s, called 358 light buff. A color that evolved later.
http://www.titanic-cad-plans.com/whitestarbuff.pdf
... etambot ...

Pascal, thank you for the very interesting story on 'White Star Buff'! But I'm not sure they were the first to use the colour, I think there are quite some other uses decades earlier than that.

And also very interesting to learn the systems used nowadays for propeller shafts. You mention oil lubrication from the 'etambot': I guess it's French for the stern post?

But regarding the use of stainless steel, I have to concur with Wefalck here: although stainless steel had been developed as early as beginnging of the 19th century, the use of it for a part as large as a propeller shaft was neither feasible nor possible, and not necessary either. Ordinary steel usually has sufficient strength and toughness to withstand the torque forces, so why wouldn't they use that? Only the problem of rust remains, so protection is required. As there are many examples of shafts (not tubes) painted in antifouling, I wouldn't find anything else a very logical choice. On many shaft even today 'zincs' are attached and revolve with the shaft, as a further measure to abate corrosion. And, lubrication of the shaft bearing in the A-bracket can also be accomplished very well through the arms of the bracket.

Reference to Nomadic as a very similar ship for comparison makes sense, but what makes you certain that that ship originally had stainless steel shafts, instead of having them recently added? And what about Hydrograaf: of course we may ask the owners what the shafts are made of, today and even originally.

Maybe this post is useful in this context: viewtopic.php?f=69&t=101353
Regarding however the picture I posted there of the Smit Rotterdam, I am now becoming careful, you might be right that ship did have tubes around its shafts. I can investigate into that.

Etambot is stern tube.

The shafts were made of forged steel (much stiffer than stainless steel which is rather "soft" and easy to bend). But if you look at the Olympic class shafts, they were covered with a bronze bushing to avoid corrosion.

Titanic the Ship Magnificent Vol 1: Design & Construction:



Capture from my book:









For the stern shaft bearing, it is possible that it was lubricated with seawater like the Titanic thrust bearings and like some of the small pleasure boats of today.

I'm not saying that the white star yellow was the first one, but that it looked like it, and it is well documented.

I have sailed on 3 tanker ships dating from the 1980s and 1990s with two propellers and I can confirm that on all, the shafts were protected by tubes filled with oil under load, there were fitted with two packing, one on the aft chair and one ont bulkhead side , the oil tanks and their level being placed a few metres above the maximum draught, . This is to pressurise the tube positively in case of a leak, to prevent seawater from entering the bearings, and to compensate for the difference in density between the oil and the seawater.

Cathodic protection zincs have disappeared on large modern ships, replaced by active cathodic protection, with anodes and cathodes integrated into the hull.

This electrical counter-current is controlled by an electrical cabinet in the engine room.



Anode/cathode Cathelco ICCP fitted on the hull, personal pictures:







Other active anodes and cathodes are also installed in the seawater filters of the engine room intakes, which serve to protect the interior of the seawater pipes of the engine cooling systems.



https://www.youtube.com/watch?v=_iXv8hk ... oamerRealm







https://static.shipparts.com/3ba7bb8bfe ... c59f54.pdf

DrPR wrote: .....And for Pascal and other 3D modelers you might try molding the line into the hull. In the shipyard they often welded a small bead on the hull plating to mark the waterline so when the ship is in drydock for hull painting it is a no-brainer to get the waterline and boot topping correct. Hull numbers and letters were also marked this way.

Think what the hull numbers and lettering would look like if it was up to a sailor hanging over the side or on a rocking float to try to guess which way was horizontal and how large the letters and numbers should be! With the welded beads it was just a paint by number job, no more difficult than a child's coloring book.

Phil

An exemple Phil, personal pictures:

Thanks. Somehow I was not aware that brass liners were shrunk onto the propeller shafts, when these were supported by A-brackets. The drawings for TTITANIC indidate that the A-bracket bearing actually runs on the brass liners, rather on the steel shaft. Interesting. I have to have a look in my early 20th century shipbuilding handbooks to see what they say about this.

Hi Pascal,

Thank you again, I learn a lot from your expertise! The use of bronze liners (not brass, Wefalck!) to forged steel shafts is also new to me. But it must have made sense then, although it must have costed a fortune. If however the exposed part is bronze, then the use of antifouling wouldn't be feasible.

But now back to your model of Hydrograaf: I don't see bronze coloured shafts, but steel, stainless or forged. You referred to Nomadic, but these were stainless steel as you said. Didn't you also say just above that stainless steel is too soft?

Maarten

Maarten, the excerpt from the book Pascal showed mentions brass not bronze - but I wondered myself, as bronze would be a much better bearing material, particularly, if it contains some lead.

In your picture of the Smit Rotterdam, it's a protective tube filled with oil. Typical mount.

Sometimes the anodes are covered with non-water repellent grease to prevent the paint from sticking when the antifouling is applied. The grease is then removed or left alone once in the water.

On this picture, it is also possible that the painted anodes are replaced later after painting, as on the rudder, paint touching up is then done at the welds once the new nodes are installed.

There is of course an inspection of the hull by the technical director in charge of the work, the chief mate and the chief engineer before putting the dock in the water



Classic oil circuit for lubrication and sealing of a stern tube, with the protection tube, it's the same.



If the seals on the propeller side break, the oil leaks into the sea water, and it is urgent to remedy this leak, which is not rare. This can be caused by a cable or fishing line being wrapped between the shaft and the propeller, or a piece of hawser.

This has happened to me several times in my career.

Usually a diver is brought in to remove the line and see what damage has been done.

Either it is possible to ballast the ship sufficiently on the nose in order to get the shaft line out of the water and replace the defective fitting with a new one. This is very rarely possible.

Or it is not possible, and the leakage is not too great, the contaminated and ineffective oil is drained off with seawater and replaced with a very special oil of density near 1 which is miscible with seawater, but very expensive and allows effective lubrication of the bearings. This means that the next technical stop of the ship in dry dock can be awaited with peace of mind.

Hydrox oil :
https://vickers-oil.com/wp-content/uplo ... -Rev-6.pdf

The third and most expensive solution is to immobilise the vessel and put it in dry dock with the consequent delay towards a free dry dock and the loss of commercial exploitation.

In the most serious case I have experienced, we had to continue operations on one engine and one shaft line for a month, while the dry dock was freed up, and the new mechanical seal was manufactured in Japan, then flown to the West Indies on the other side of the world. It is not very comfortable to sail in this way on a 110 meter tanker.

In this case we spent 3 weeks in dry dock, the propeller shaft chair had moved, which involved removing the shaft line by uncoupling it from the engine gearbox, laser aligning the chair bearing by machining the chair with a portable lathe to fit a new, well aligned bearing. A big job for the specialists.

Note that it is much easier to let a moorings line run on ships that have 2 or 4 shaft lines than one, the propellers are then in line with the stern manoeuvre. "Beware of Propellers" !

For this reason we avoid using the propellers on the quay side once the lines are sent to the quay, but this is not always possible, due to weather conditions, current, etc.

Ecologic aspect of the leak:
https://www.maritime-executive.com/corp ... productive

The elements have been printed, especially the windlass.

Only the small hand winch remains, and some painting to be done.







The 4 vents and 2 stove pipes, probably one for the cooker, and one for the front cabin heater.

Thank you to everyone for the dissertation on 1:1 ship practice! The rigidity of a forged shaft has practical aspects. In the case of multi screw warships with fine lines, some of these shafts are very long. Where a differential in stiffness between the hull and shafting can be problematical was in shock damage from whipping as a result of underwater damage from torpedo or mines. The RN Prince of Wales suffered extensive damage from a torpedo hit causing the rotating shaft to seriously damage the shaft alley. My recollection is that Battleship Pennsylvania suffered a similar near loss from shaft alley damage, though she was not underway at the time.

The forging and turning of such large items is a very specialized shipbuilding undertaking.

As always, interesting! Tom

Tom,

The notes on ship's blueprints often tell how to manufacture a part. The Cleveland class cruiser propeller strut drawings say they have a 4 foot diameter hub with 12 foot struts, cast as a single part (1/2 inch oversized to allow for finishing). The struts were hydrodynamically "streamlined" and twisted through the length to match the direction of water flow around the hull.

Then the struts were mounted to the hull and machined in place for the shaft bearings to be aligned with the other bearings for the approximately 300 foot long propeller shafts (about 30-50 feet were outside the hull).

It boggles my mind to think about machining a 2 1/2 foot diameter hole for the shaft bearings in place on the hull of the ship!

I would love to go back in time and wander around in the shipyards while they were building these ships.

Phil

Thank Phil for the informations.

It boggles my mind to think about machining a 2 1/2 foot diameter hole for the shaft bearings in place on the hull of the ship!

I think the chair was pre-drilled in the foundry. This would reduce the machining time of the bearing housing.

I have seen this type of machining as described above, it is quite impressive in its precision.

The laser beam was in use and measured the alignment continuously for several days.

You could see on the graph, the hull twisting on the tins with the temperature differences between night and sunny days.