Open and closed Shelter Deck vessels

[j.sabourn]

Anyone know if there is still a demand for such vessels. Most tramp ships of the 50"s and early 60"s had this capability of open or shut. Could usually tell before going onboard if had such capabilities as would be a second Deck line cut into the shell plating above the plimsolls. The deck line mark was always considered the uppermost continuous deck which usually was the working deck. And if going down to your marks was best to be in the closed position as your deadweight would increase. However if were not going down to your plimsolls, the open shelter deck was more convenient. To change from one to the other was to take the steel doors off the Tween deck openings between holds to become an open shelter deck vessel, this also altered your gross and net tonnages for the payment of Harbour and light dues, this seemed to disappear on most vessels through time and no doubt the regulations have changed over the years. Also for those not aware of ships tonnages when describing ships sizes etc. most seamen talk about the deadweight which is the amount of cargo a ship can carry, a passenger ship I should think would be described in a different manner. When talking tonnages You Have Displacment tonnage (light or unloaded) Displacement Tonnage ( loaded) the difference between the two being your deadweight. Gross tonnage and Net tonnage which are cubic measurements of different spaces on ships, cargo, engine accommodation etc etc, and used to be calculated at 100 cubic feet to the ton. Different countries in some cases had different methods of calculating this cubic, for instance American ships a bale of cotton was a standard size and had to be able to get such through an opening to be able to calculate this for the relevant tonnage. Then you had suez canal tonnage certs. which is one of the reasons why the forecastle head was always cleared out of stores before transit, otherwise would be considered a cargo space and up the dues. Believe a similar post has already been on here before, but for non seafarers will give you a rough idea that tonnages are not all one thinks they are. A recent post on Russias hoped for new destroyer is 16000 tons displacement and this is the actual weight of the ship, probably as heavy as some of the old battleships. Cheers JS

[Ivan Cloherty]

Still see many trading around Singapore, Philippines etc serving the thousands of islands in that area, where cargo separation would be essential for the trade. They bring back many memories of getting hatches and derricks ready for load or discharge or in a lot of cases, both at the same time, sometimes in the same hold.

[John Arton]

John S
Naval vessels do not have load lines. Regarding shelter deck vessels the SD14's from A and P in Sunderland and built under licence around the world in there hundreds, were all shelter deck ships. SD14 is shelter deck, 14000 tons. Believe the Japanese Freedom ships that came out to rival the SD14 were shelter deck also.
Also what about the tonnage hatch, a small hatch, usually fwd or between nos 1 and 2 holds, that had a bolted cover and was always empty and unused for cargo.
The Beaverfir had one and for some reason that I forget now, it was necessary to sight the spare anchor, yet no one could find it! I was cadet at the time and in my exploration of the ship, out of curiosity I had actually been into the tonnage hatch and recalled seeing a large crate in there so I went back down and prised open a part of this crate and lo and behold found the spare anchor. Brownie points all round!!!
rgds
JA
rgds
JA

[Ivan Cloherty]

You must have been on modern ships John, as far as I recall the tonnage hatch was always aft of the aftermost working hatch, usually #5 or #6, the spare anchor bolted to the foc'le bulkhead, if vessel had a foc'le or against the for'd bulkhead of the poop housing and the spare prop kept in the tonnage hatch or the aft end of #5 tweendeck, as it was always reckoned you would need a spare anchor before using a spare prop. These things were always put on board by cranes whilst the ship was building with no thought of how those on board were going to get at them when derricks neither plumbed over the tonnage hatch or the foc'le. Happy days!

[j.sabourn]

Thought SD 14s were smallish bulk carriers, but maybe getting mixed up. Never been on a bulker with tween decks. Probably am getting mixed up as just come in from another night out. Cheers JS

[j.sabourn]

#14 I know naval ships don't have plimsolls however they do have draft marks. Plimsoll are named after Samuel Plimsol who was after the shipowners who were overloading their ships and losing lives. Warships do have displacement tonnages which is how they are described. The average non seafarer is not aware of tonnages as such and was an attempt to give them and understanding of shipping in general, and that tonnage did not always mean weight. Cheers JS

[Captain Kong]

SD 14s were a replacement for the SAM boats that were coming to the end of their time. SD, Standard Design. so building was easier as were all the same deign and measurement. tho` I never sailed on one I did sail on Sam boats.
Brian

[Ivan Cloherty]

SD 14s were a replacement for the SAM boats that were coming to the end of their time. SD, Standard Design. so building was easier as were all the same deign and measurement. tho` I never sailed on one I did sail on Sam boats.
Brian

SD14's were all tweendeckers, with varying types of deck gear, Freedoms were a larger deadweight and standard design had folding tween decks which when placed verically converted the vessel into a bulker with inbuilt feeders. Most were fitted with Thomson swinging derricks (cheap crane subsitute) very slow for working general cargo. Deck and hatch strength on the Freedoms was much better than the SD14, so less worrying from a deck cargo point of view. As usual stand to be corrected, but this is from what I remember when looking for vessels to take on time charter

[j.sabourn]

As said the real point of this post as regards tonnages is for those not aware. Manys the time I have read the such and such vessel then quoting a tonnage figure, feel like shouting what tonnage are you referring to. The biggest users of this non information is the Press. Probably purely just plain ignorance on their part as will print anything to make a story sound feasible. Most cargo ships of the 10,000 ton deadweight variety usually had a gross figure of about 5,500 and a net tonnage of about 3,500 tons. They usually quoted whoever was around at the time, and putting out stories which meant different things to different people. However whatever story the press put out about anything, think most people have learned to sit back and wait for the truth at a later date. JS

[Captain Kong]

just looked at my old discharge book.
the SAM had a net 4304, gross 7131, similar to a Fort. Gross was around 10,000 ish
Brian

so a 4000, ton ship could be a 7000 ton ship or a 10,000 ton ship, in the Press depending on what seems the most dramatic for the story.