Model Boat Mayhem
Technical, Techniques, Hints, and Tips => Other Technical Questions... => Topic started by: Bryan Young on February 15, 2008, 07:06:58 pm
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Looking at the various postings I found myself wondering if there is a place on the forum for posting about little known items of ships equipment and how they were used.
As a starter, may I introduce the mechanical deep sea sounding machine. Even with the advent of the now ubiquitous "Echo Sounder" many ships right up into the early 1970s had these.
Whereas a "hand lead line" would normally be used to indicate a shelving sea floor ( or give an indication of the nature of the sea bed), the "deep sea" version could sound out depths well in excess of 100 fathoms....which made it ideal for letting the mariner know when a continental shelf was being approached. Before the days of (now defunct) Decca Navigator, Omega etc. when ships still relied on the sextant and chronometer, if the ship had been in overcast conditions for a few days then all navigation would have to be done by Dead Reckoning. Not always accurate. So any aid was useful. Even when Decca was around it didn't cover all coastlines.
The drawing is basically self explanatorybut 2 items may be puzzling.
1. The "arming cavity":- This is just a recess in the base of the 30lb lead sinker. This cavity would be filled with tallow or some such so that when the sinker hit bottom it would hold a sample of the sea bed. This would tell the navigator if the sea bed was of mud, shale, gravel or whatever. Compare that to the chart and you would have an idea (no more) of what area the ship was in.
2. As the ship would be moving at the time of casting, or if stopped an underwater current could carry the lead away; the length of wire paid out would or could be inaccurate. Hence the glass tube fitted into a brass cylinder. The glass tube was closed at the upper end and the inside was coated with a water reactive chemical. Pressure would force water up the tube to a particular point. On recovery the glass tube would be laid on the graduated "boxwood scale" and the length of the discolouration would be converted into fathoms.
Just a thought.
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I have used them many times in the days before all ships were fitted with radar.
very useful approaching grand banks in for Etc
Dave
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Some time ago a forum member asked about "Oxter" plates. Pics are better than words, so see if this works.
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"As the ship would be moving at the time of casting, or if stopped an underwater current could carry the lead away; the length of wire paid out would or could be inaccurate. " - So how accurate could these things be?
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If the ship was stopped and no underwater current was affecting the sinker then when the line went slack as judged by the "feeler" the result was reasonably accurate to within a fathom or 2. If the ship was moving or there was a strong underwater current then obviously a simple length of wire depth would be impossible to interpret. Hence the closed glass tube. If (and it was always a big "if") the sinker did not fall over then the water pressure inside the tube would, like a Fortin barometer give a very reasonable indication of the depth of water....and also the nature of the sea bed......it isn't all mud you know!. But I do know that it was back-breaking work to wind that damned wire in again. Cheers. Bryan.
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Done the back end, now for the front. You will notice that no "stealer" plates are used. Either the drawing is inaccurate or else early "Iron" builders were happy to have very narrow strakes. Not sure which is true.
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Hi Bryan
You might be better starting a new thread for Plating.
Although you have changed the subject in the new post, it is still the old subject (deep sea sounding machine) at the top of the thread.
I only mention this as it deserves another thread and people may miss it. I know there are lots of modellers who are very interested in plating and it would be sad if the missed it. :)
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Evening Tiger.
I actually started this thread just to put on some pics, info etc. on bits and bobs that are seldom seen today and couldn't think of anything else to call it.
Just a simple thing comes to mind...stuff like how many are aware that "Fire Buckets" had rounded bases so that they couldn't be use for anything else. Stupid stuff like that. I agree with you but will leave it to a moderator.
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:angel:
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Topic name changed as requested. Colin
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I think this is a great thread Bryan and I particularly like the plating drawing. I suspect that stealer plates would be weaker than thinner strakes when they are surrounded by rivet holes so that might have something to do with it. Only a guess.
Your first one brings back fond memories of my early days when we used to actually put out a speed log for transatlantic crossings. Showing my age now.
Actually that would be a good one for you to describe because you have why they called it a log and how the speed came to be known as a knot all in the same description.
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Actually, Bunkerbarge, you beat me to that notion by a few seconds! You are talking about the Walkers Log. A few tales of the 2nd mate being tipped over the side at midnight when reading it....and of sharks eating the impeller. But thats for another day...tomorrow if it is as cold as today has been!
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Plating.3
Another "oldie" of the "back-end"
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Plating 4.
Just posting this one to give an idea of the run of plates and the shift of butts...remember that in all but a few special cases the longitudinal plates overlap with the raised end facing aft.
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Wood Deck Houses.
The pics here were taken by Ray Thompson of TMBC.
Just to make a break from all the ironwork!
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Wood Exterior Doors.
They come in many guises, but these are typical. Not really too difficult if you use thin veneer as layering
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The "Log".
Not the ledger sort, but the speed/distance recorder.
A quick bit of history first. Before mechanical devices were invented the "common log" was used. Very simple in basic practise. A wooden reel with a line wound round it, a chunk of wood (the "log") and a 14 second "egg timer" sort of thing. The "log" was a triangular piece of wood weighted to float upright and attached to the line with a 3 legged bridle. The line was divided into equally spaced segments by knots. When the "log" was chucked over the side the glass was upended. When the glass was empty the line was held and the number of knots counted...and then a rough claculation was made which gave the ships speed through the water (though NOT over the ground). So there we have the definition of "knots" and "log". It is incorrect to say "knots per hour" as it was only measured for 14 seconds at a time. Also remember that a nautical mile at 6080 feet is considerably more that a statute mile of 5280 feet. A nautical mile is 1 minute of arc at the equator...makes more sense to me that some arbitrary figure dreamed up for the statute mile. End of early history.
The later "Walkers Cherub" mechanical log only measured distance (through the water again, and not over the ground), but using time and distance speed is easily ascertained(ish). The "clock" part of the Cherub has 3 dials. The large dial goes from 0-100 miles, one of the smaller dials shows 10ths of a mile (optimism!) and the third shows 100s up to 1000 miles. Immedately aft of the clock is the governor which smooths out the rotation of the plaited line. About 60 fathoms of line would be used on a ship doing 15 knots (360 feet). Quite a length really and often fouled by fishing vessels and such. Just in front of the finned rotator is the "fish" that connects the line to the rotator. The rotator fins spin the rotator and onwards to the clock. And thats about it really. This system was almost universal until the introduction of things like the hull mounted pitot tube (Chernikeef) type. The gleaming brass rotators were irresistable to sharks who would regularly bite the ruddy thing off.
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O0
This is great stuff Bryan,
Quite uncontroversial,
;D
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The dreaded "Load Line" (Plimsoll line).
A pretty common problem for modellers is the placing and drawing of the "load line". Perhaps this will help.
Not all ships have the same markings. This can depend on the trade they are in (tankers have different marks to dry cargo ships), and the waters they usually trade in.
The "Assigning Authority" (I shall assume Lloyds, but there are many others nowadays) is marked by 2 letters, one each side of the "disc". Lloyds is L.R. ..The pic is the marking (chiselled into the hull plating to prevent cheating...as if they would) as seen from the starboard side of the vessel. Reversed on the Port side.
The "Deck Line" mark is the datum point for measuring the ships freeboard. Freeboard is more important than draught to the authorities, and rightly so. This mark is at the level of the uppermost continuous deck (main deck) level which in turn is the deck at which the bulkheads stop. That is why "open shelterdeck" ships have the deck line marked a lot lower than would appear necessary.
All lines are 1" thick, and measurements are taken from the lower edge. This makes a difference if you consider that a reasonably sized ship can have a TPI (Tons Per Inch) increase in draught of perhaps 60 tons or more. Loads more money for somebody!
Abbreviations:-
S = Summer Load Line.
W= Winter " "
WNA= Winter North Atlantic.
T = Tropical LL
F= Fresh Water LL
TF= Tropical Fresh Water LL
There are rules stipulating the various gaps between the lines, but I don't really think a modeller need worry about them.
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CHERNIKEFF LOG. All hell broke loose if "the log" wasn't pulled up before the ship docked. ie no request from bridge or lack of time to do job when getting ready for manouvouring main engine and forgetting. Dont know why but it was always the J/Eng that got the stick. Bottom of the heap I guess.
Oh well, just have to drive it out the bottom and fit the spare, if replaced after the last time. Lovely looking piece of brass tubing with enclosed rotor at lower end.
On another ship there was fitted a different type, one that could be rotated 180 deg and doing so it failed to record, And then there was the midnight call to pull it up to wipe the weed of it. Always at end of a watch/ middle of handover?
Great days, you shouldn't join if you couldn't stand the strain. Good theme Brian. BF
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CHERNIKEFF LOG. All hell broke loose if "the log" wasn't pulled up before the ship docked. ie no request from bridge or lack of time to do job when getting ready for manouvouring main engine and forgetting. Dont know why but it was always the J/Eng that got the stick. Bottom of the heap I guess.
Oh well, just have to drive it out the bottom and fit the spare, if replaced after the last time. Lovely looking piece of brass tubing with enclosed rotor at lower end.
On another ship there was fitted a different type, one that could be rotated 180 deg and doing so it failed to record, And then there was the midnight call to pull it up to wipe the weed of it. Always at end of a watch/ middle of handover?
Great days, you shouldn't join if you couldn't stand the strain. Good theme Brian. BF
Why on earth did a J/Eng have to do it? As a bit of bridge gear it was my job as 2/O (deck) to launch myself down a squillion decks, open the hatch to the duct keel and wind the "xxxxx" up myself. Then (later) when leaving port do it all in reverse. Except it now needed re-calibrating. Honestly, until someone decided that we had suffered enough and fitted a motorised version it made life hell. I believe they call it character forming nowadays. BY.(Grumpy old man).
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In USSCo it was in the ER by ford bulkhd on the "slow green" that I was on, and in MAORI , was if I remember right, at the aft end of the stokehold. I stand to be corrected by someone with a better memory, it was a long time ago now. But it was a lovely piece of brass tube, I'm sure if I had it now I would find something to use it for. Cheers Bryan. BF
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The Telemotor.
This was pretty well ubiquitous until being overtaken my the more modern electronic "joystick system.
I don't think this needs any further explanation.
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A Small Steam Windlass.
This must be the smallest steam windlass I have seen (the white patch is an A4 sheeet of paper). Also capable of hand operation.
I don't know its age, but it has to be knocking on a bit. I imagine it was fitted to a small tug, possibly a fishing boat or somesuch, but the pics show its operation pretty clearly. Pictures by Ray Thompson.
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The Fire Bucket.
Sand filled. Another reason for this post is to show how uneven the caulking can be, and also the weathered colouring of the deck planking.
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All interesting stuff again Bryan and great resources for puttin g together a model.
The winch is interesting in so far as the cylinders are vertical and quite nicely done with wooden lagging, that has already given me an idea for my own steamer!!
The caulking is interesting as you rightly say it isn't always even. It starts out peerfect when fitted and sanded down but repairs over the years are very rarely done with the planks lifted so caulking is simply laid over the top of the deck giving an uneven effect. I've already built some of this effect into my decking, to make it more realistic of course!!! ::)
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All interesting stuff again Bryan and great resources for puttin g together a model.
The winch is interesting in so far as the cylinders are vertical and quite nicely done with wooden lagging, that has already given me an idea for my own steamer!!
The caulking is interesting as you rightly say it isn't always even. It starts out peerfect when fitted and sanded down but repairs over the years are very rarely done with the planks lifted so caulking is simply laid over the top of the deck giving an uneven effect. I've already built some of this effect into my decking, to make it more realistic of course!!! ::)
I was quite fascinated with this little windlass as it appears to be back to front! The spurling pipes which have to be behind the windlass are at the opposite end to the cylinders. Very strange. Ta for reading this little lot. Remarkable what I can find to do while waiting for my lathe motor. Bryan.
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Deck Planking.
There have been a couple of posts recently on this post wanting info...so here goes.
The drawing is to no particular scale , but as said earlier try thinking about 4" wide, although not many will notice if the scale is a bit "out". The ship side guttering ( or waterway or whatever you want to call it) is probably between 9" and 1' wide.
The Margin Plank is wider than the deck planks, and its joins should'nt line up with the adjacent deck planks...so these can be any length that suits.
In this example I have used a 2:4:1:3 pattern which I find quite pleasing at a model scale. Try some others, but try to keep the separation of butts at the maximum. Lay the planks from the centre outwards to keep it regular, the centre plank straddling the ship centre line.
All "holes" cut through the deck should be surrounded by margin planks as shown....not to scale, just to give an idea.
Short lengths of plank should be avoided. I have included a few on the drawing just to show how silly it can look. But the continuation of lengths should be regular otherwise the butt lines will be all over the place.
Hope this one helps....
As I keep getting a "Windows cannot display this page" message I will again do it in 2 parts. BY.
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Deck Planking Part 2.
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Back to Shell Plating.
Shift of Butts: only 1 simple rule as far as model makers are concerned. Butts in adjacent strakes must be at least 2 frame spaces apart. For modelling purposes use 24" for frame spacing.
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The Plated (or solid) Bulwark.
1. Stanchions (or stiffeners) not more than 6' apart.
2. Freeing ports. This drawing explains the operation better than my earlier posting re. how they are self-operating using gravity. Noisy sods though. Clanging away all day and all night!
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Sternframe, Single Plate Rudder and Twin Screws.
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Bryan was beginning to feel a bit lonely on this topic despite the useful material he has posted so I thought I'd chip in.
The illustrations below are taken from "Scale Model Ships" first published by Reeve and Thomas in 1951. I got my copy as a Form prize at school in 1962, the only time I ever came top of the class. sadly it's been all downhill ever since... Although model boating was a bit primitive in those days I still find some of these drawings very useful references both for their subject matter and their clarity so I thought it was worth posting them.
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And a few more...
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Nice thread Bryan and a great idea.
I well remember the "Deep Sea Sounding Lead" but have to admit never having seen it used, no matter how long we were sailing by DR.
On the subject of "strange" items, has anybody heard of, or seen used, a "Jim Crow"? I have once. Kept, and used by, "Chippie" it was a form of Crowbar [hence the nickname] used to straighten removable railings which were taken down while working cargo with the ships gear. As such they were subject to a lot of hammering.
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Nice thread Bryan and a great idea.
I well remember the "Deep Sea Sounding Lead" but have to admit never having seen it used, no matter how long we were sailing by DR.
On the subject of "strange" items, has anybody heard of, or seen used, a "Jim Crow"? I have once. Kept, and used by, "Chippie" it was a form of Crowbar [hence the nickname] used to straighten removable railings which were taken down while working cargo with the ships gear. As such they were subject to a lot of hammering.
Tell me more. This is a new one to me. BY.
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Thank you very much for an absolutely great thread. I not only love the history, but I have started a file directory called “How to Make”.
More and more please.
Don
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Brian
"JIM CROW" The one I had an "opportunity" to use took 2 BIG apprentices to lift while "the man" carried the CROW BAR. We were using it to bend or straighten railway irons. Never saw "chippy" with one but all would work the same. The "bar" was put across the claws and pressure bought to bear by the movable head attached to the end of a heavy square threaded screw that was turned by the 6ft crow bar put into the hole through the boss at its head. it was shifted as required to make the bend or correction to a bend. Just a bit at a time.
Bob Ferguson, NZ