Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Working Vessels => Topic started by: funtimefrankie on March 24, 2008, 10:45:52 pm
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Am I right in thinking that a tug won't have load lines - Pimsol lines and the like?
Frank
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well my Happy Hunter has some load lines etc
stavros
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does that mean tug Kenny's red pelican will have lateral lines ,like fish have {-) .
daz
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Just cjecked half a dozen different real tugs from my image collection. All have depth and plimsoll marks.
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Mine has a little flag on the funnel
Ken {-)
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Mine has a little flag on the funnel
The way your boats behave Ken, that's probably the only bit showing! {-) {-) {-)
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You sure thats not a periscope instead of a flag {-) {-) {-)
Jay O0
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Perhaps depends on the era. Late model tugs- seem to have the Plimsoll. Earlier (1930s for sure)- Not.
Most all will have draft marks... Roman or Arabic.
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ALL vessels used for commercial purposes 24m or over are required to have a loadline.
A loadline does not measure draft, it is a measure of freeboard, or reserve buoyancy. The freeboard is calculated on a state of loading which will leave the vessel still able to float if a compartment is breached.
The loadline rules came into being in 1894, though the present rules that are now in force are dated 1966.
DRAFT MARKS.
Now mainly metric, the metric marks read every 20cm. the marks are 10cm high.ie
2.40
2.20
2.00
The base of the numbers is as read ie 2.0 is 2metres. The top of the numbers are the odd readings ie top of 2.20 is 2.3m.
imperial marks are 6 inches apart, ie the bottom is the number read again, XI is 11 feet, the top of the XI is 11 feet 6 inches.
Andy
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Andywright is absolutely right!! {-)
Well put and explained!!
SS Daring
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The type of load line will depend on the era issued and for the area the tug is surveyed to work in some dock tugs have just a straight line cut at the maximum draft permitted amidships. There is or was , not sure if it is still in existence a diamond load line for partial smooth water limits and a vessel surveyed for smooth water limits had no loadline what so ever and this was the case in the 1960's. Vessels required to work outside these areas always had a Plimsolls loadline, this altered with the letters and depth lines accordding to what area it was surveyed to work in. A vessel surveyed to work between London and Hull would only have a summer and a winter line cut in, so yes all vessels that go outside smooth water limits do have a loadline cut in, but what type can vary slightly, I forget the rule on just the straight line but it is to due with carrying no cargo and a special dispensation from the MCA.
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Okay chaps....All very interesting but what on earth do I put on a Tug from 1890 that would have crossed between ireland and the North of England?
Barry
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what is the circle thing in the middle, heck whats all the stuff in the pic
(http://i136.photobucket.com/albums/q162/bigfordf550/plimsoll_line.jpg)i like answering my own questions
(http://i136.photobucket.com/albums/q162/bigfordf550/p0011334-plimsoll-line.gif)
but what dose it all mean???
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Differing dencities in waters will give a vessel different drafts
TF ships draft will be deepest
F ship will float higher in the water
T ship will float higher in the water
S and so on
W
WNA
Then the (London country bus sign) is the load line awarding agency [ L R ] Lloyd's Registry other's B V / N V etc
if you note that the SW salt water line is the same as the registry line
R,
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Differing dencities in waters will give a vessel different drafts
TF ships draft will be deepest
F ship will float higher in the water
T ship will float higher in the water
S and so on
W
WNA
Then the (London country bus sign) is the load line awarding agency [ L R ] Lloyd's Registry other's B V / N V etc
if you note that the SW salt water line is the same as the registry line
R,
Just out of interest but does anyone actually check the Plimsol Line when ships are being loaded or is the cargo weight and hence ship's draft all worked out by computie nowadays?
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Yes load lines are checked,
well they are in the case of the ships I have worked on, not so much with tugs as once you ballast down youare "on your marks" and that is that sort of thing unless you take on deck cargos there isn't much change while working other than a reduction in draft due to fuel useage.
The loading of a large light weight cargo may require the use of water ballast, this would be loaded until the load line is reached but it would be possible that not all the ballast tanks would be pressed up in order to trim the vessel port/stbd and fore/aft.
Most vessels now have loadline indicator systems within the bridge area, the loading mate can request ballast to be moved, ejected or loaded to aid the stability of the vessel etc.
R,
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You should see the skipper on one of the boats that comes to Goole ,whilst been loaded he is up and down the quay checking the draft and making ajustments with the stevodores (to their annoyance) as to where the cargo is placed in the hold.
daz
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The incentive to not go below your marks is the fine impossed on the master, as a overloaded vessel is considered an un safe vessel. The fine is in the magistrate court max £55,000/ two years in prison or in crown court unlimited fine/prison sentence. Plus you can loose your certificate and your job.
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Yes all so true
until you enter the realm of dredgers! they load over their loadlines, then when the water content is drained the vessel (with a bit of luck) floats at its loadline.
MCA and Lloyds etc know this and that how it is.
How do I know 8 + years on agg dredger and several on clearance Agg is cleaner ::)
still even with 18 inches of water on the main deck the old tub stayed afloat which can give you an insight to the amount of safety there is in the possition of the loadlines
R,
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Differing dencities in waters will give a vessel different drafts
TF ships draft will be deepest
F ship will float higher in the water
T ship will float higher in the water
S and so on
W
WNA
Then the (London country bus sign) is the load line awarding agency [ L R ] Lloyd's Registry other's B V / N V etc
if you note that the SW salt water line is the same as the registry line
R,
One of the reasons for the mate (just good chums, rally) dashing up and down the quay is really to check on how far he CAN go over the marks and still be legal when he gets to sea. An example. Loading "Olna" in Devonport. The water salinity could be 1010. At sea it would be (give or take) 1025. This would mean that for this ship, the ship would rise 4" . Now for an RFA it doesn't matter all that much, but for a commercial ship with a TPI (Tons Per Inch) of perhaps 70, that means the ship can load 280 tons more of paying cargo. Not to be sneezed at. But it all depends on where the ship is going and what zones she will cross. Not really a subject for this forum unless someone is REALLY interested and not just pulling the wool.
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cheers BY , i can see where your coming from there and understand that the load lines are relay important ,the thing is with the ships that come into goole (for RMS) they tend to rub to Duisburg and rotterdam so not sure if what the difference is with the water apart from salty in the sea and fresh in the Rhine ,also i suppose the draft is also important as the depth on the Rhine can vary . there are two pride ships ,Vere and Brail that come to goole with containers and they are used specially because of their shallow draft for the Rhine.(have i answered my own question??).
daz
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cheers BY , i can see where your coming from there and understand that the load lines are relay important ,the thing is with the ships that come into goole (for RMS) they tend to rub to Duisburg and rotterdam so not sure if what the difference is with the water apart from salty in the sea and fresh in the Rhine ,also i suppose the draft is also important as the depth on the Rhine can vary . there are two pride ships ,Vere and Brail that come to goole with containers and they are used specially because of their shallow draft for the Rhine.(have i answered my own question??).
daz
What do you reckon the TPI of a tug at? 15 perhaps? Negligible. They probably just load to the FW mark every time.
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As for TPI regarding tugs they don't normally carry goods so therefore you should find that when in full fuel bunkers you would fill water ballast until the load line, this is pertaining to the water the vessel is in.
as fuel is used then more water ballast it taken on board to maintain the L L.
The amount of 'deck cargo' allowed on tugs is normally quite low in weight and in my own experience not done very often as the payload is not enough to equal the cost of running a large engine for such a small cargo.
IE; Medium tug = 3500 Kw possibly carry 10 tonne
Ship 3500 Kw carry several thousand?