Subject: SMML VOL 2789 Date: Sat, 26 Mar 2005 01:32:46 +1100 The Ship Modelling Mailing List (SMML) is proudly sponsored by SANDLE http//sandlehobbies.com For infomation on how to Post to SMML and Unsubscribe from SMML http//smmlonline.com/aboutsmml/rules.html ---------------------------------------------------------------------------- MODELLERS INDEX 1 Re New (?) Aoshima and Bismarck kits 2 Re Sub prop - this way or that way? 3 Re Sub Prop rotation 4 More on underwater searching 5 degaussing / towed cable 6 Sub prop rotation 7 OTULCC Tankers 8 Etched brass railings 9 Re Sub prop - this way or that way? -------------------------------------------------------------------------------- TRADERS, ANNOUNCEMENTS & NOTICEBOARD INDEX 1 Announcing, officially, finally, the Ship Kit Review list version 6.4!! ---------------------------------------------------------------------------- MODELLERS ---------------------------------------------------------------------------- 1) From "Daniel A. Kaplan" Subject Re New (?) Aoshima and Bismarck kits >> I have discovered an announcement for two new Aoshima kits of german battleships "Bismarck" (No.#3423) and "Tirpitz" (No.#3424) in 1700 scale, which come together with Tamiyas Z-23 destroyer. Does anybody know, whether Aoshima still used their old molds from the 1970s or whether it is a totally new kit from this japanese manufacturer itself or maybe a tool-sharing with Trumpeter or Dragon, which have released this models last year? I didnt find any information, only a note that Aoshima did a good job by researching extensively and also that they added a separate sprue on wich are the parts which make the differences between both ships. << Axel This is a brand new tooling. No one here has yet given it a review but Model Graphix Japan has done a photo/review in its April 2005 issue. There's a side by side by side comparison of the Dragon, Pitroad, & new Aoshima versions. I don't read Japanese but the photos are very good. Incidentally, there's also a magnificent 1/700 build of the Hood by Seikaro Ohki, a master modeler. Dan Kaplan ---------------------------------------------------------------------------- 2) From "Ed Wandall, Aviation Research Group/US" Subject Re Sub prop - this way or that way? >> The counterclockwise motion of some propellers seen in the movie "The Hunt for Red October" has an interesting story behind it.... << Tom, didn't the model maker make them rotate the wrong way on purpose? Sort of his signature, if you will. Ed Wandall ---------------------------------------------------------------------------- 3) From ives100@aol.com Subject Re Sub Prop rotation >> It rotates clockwise when viewed from the rear. Actually, I have several photos of Sturgeons in drydock with their propellers uncovered. The Sturgeon used, IIRC a series J propeller, and that design is declassified. You can see one here http//americanhistory.si.edu/subs/anglesdangles/taming6.html The counterclockwise motion of some propellers seen in the movie "The Hunt for Red October" has an interesting story behind it.. << Seems we have a contradiction here. In addition to the above website in my previous post, you can also view here an unambiguous photo of a US Submarine propeller in drydock(Permit class, USS Barb). http//members.aol.com/vansub/dclark.jpg Looks like it rotates clockwise to me! Tom Dougherty ---------------------------------------------------------------------------- 4) From JRKutina@webtv.net (John Kutina) Subject More on underwater searching http//starbulletin.com/2005/03/20/news/story9.html Regards, John Kutina ---------------------------------------------------------------------------- 5) From Dave Swindell Subject degaussing / towed cable Hello Diderick, I missed the original question, but what you appear to be talking about re the towed cable behind the Willem Ruys / Achille Lauro is almost certainly an impressed current trailing anode. I've not seen either of these ships, but I did 4 months on the old Oriana of the same vintage which had this apparatus. I seem to remember the cable being a bit thicker than you quote, being nearer to 1cm diameter. It was a solid slightly flexible alloy wire of copper and zinc which was trailed from a special winch drum on the aft mooring deck over the stern when under way. During manoeuvring and berthing it was wound inboard. It's purpose was to protect the propellers and aft thrusters from electrolytic corrosion due to the steel hull setting up a corrosion cell. The propeller shafts are connected to an electrical device which induces a current to flow from the propellers to the trailing wire which reverses the normal electrolytic action, and causes the trailing sacrificial anode to corrode away in preference to the propellers. Dave Swindell ---------------------------------------------------------------------------- 6) From "DUANE A CURTIS" Subject Sub prop rotation To clarify the proper rotation direction for a U.S. sub is that the prop rotates clockwise direction, this comes from my years of serving onboard 5 different classes of subs in which I have seen all of them in dry dock. Duane Curtis ---------------------------------------------------------------------------- 7) From Dave Swindell Subject OTULCC Tankers Hello Kelvin Just got back from serving as 1st Engineer on a container ship, and have just picked up your message re reversing engines and stopping tankers. I don't know whether you got the wrong end of the stick, or the information you were given was duff, but all ships have to have some means of applying reverse power. On steam ships this is done by using a different turbine connected to the same shaft as the main ahead turbine. On medium speed diesel ships this is done either through a gearbox, variable speed propellers or by reversing an electric drive motor. Some ships eg the new Queen Mary have propulsion pods that can rotate through 360 degrees and thrust in any direction. Slow speed diesels however are directly connected to the propeller and have no gearbox - as you say there is no reverse gear - but by hydraulically moving the camshaft (on most engines) or altering the electronic timing (on the latest engines) the direction of rotation of the engine can be altered when starting it. The engines used on tankers are relatively small (20,000 HP would be large for a tanker, an 80,000 ton container ship I served on recently had a 100,000 HP 12 cyl engine which ran at about 98rpm) but they are far from simple, the engines and associated control gear these days is highly complex. Manoeuvring a large ship (be it an 80,000 ton container ship doing 27 knots or a 500,000 ton ULCC doing 8 knots) takes a lot of forward planning. The inertia involved is huge and they take a lot of stopping. A planned stop in a straight line would take up about an hour and cover some fifteen miles, this to avoid putting any undue stresses on the engine. The engine is programmed to slow down gradually from full sea speed of about 98rpm to Full Ahead manoeuvring 56rpm over about half an hour, then the engine is slowed manually through Half, Slow, Dead Slow and finally to Stop, waiting at each stage for the speed to drop to that corresponding to the revs. This process can be speeded up and the distance reduced significantly if the situation demands it, but the effects are spectacular. Pulling the stick back from full power to slow. will have the turbochargers (about the size of a medium size jet engine) surging, coughing and barking for a couple of minutes, the noise is tremendous and you'll be rushing for a change of underpants the first time you hear it. To start a slow speed diesel you inject compressed air (25-30bar - 375-450psi) into the cylinders through timed valves. Before you can reverse it you've got to move the camshaft, stop it, and then start it in the opposite direction. Stopping it is achieved by injecting the starting air into the cylinders with astern timing whilst the engine is turning ahead. Try doing this from full speed and you'll empty both air bottles up the chimney before you stop the engine. If you manage to start it in reverse at a lower speed you will just start the propeller cavitating and it will have no effect on slowing you down at all. Strange as it may seem the quickest way to slow down is to keep the engine going slowly ahead, this way the propeller doesn't cavitate, it acts as a brake and creates drag which slows the ship down. Once down to a sensible speed (5/6 knots) then braking air can be put on the engine with the confidence that there'll be enough air left to start the engine when it stops, and that the propeller will actually do something useful when it starts. Once the engine starts astern the ship will stop relatively quickly (3 or 4 minutes) but the whole process can take over a quarter of an hour from full speed and you've covered 4 to 5 miles in the process. Relatively high powered container ships are quite manoeuvrable, but executing turns at high speed takes up a lot of sea room. Low powered bulky tankers aren't as manoeuvrable, so though the turns are made at a slower speed they can also take up a lot of sea room. Both types of vessel handle at slower speeds (typically less than 25% power) Both types of vessel will require the assistance of at least one tug whilst berthing or picking up a mooring. Whilst under pilotage in restricted waters the vessels will operate at these reduced powers to maximise manoeuvrability. When under way at full power hazards are avoided by making small changes to course early enough to avoid them. There are of course kamikaze fishing boats, suicidal ferries, lone yotties and grey funnel ships that think they're far more manoeuvrable that they actually are who seem intent on wrapping themselves round your bows. Despite our best efforts some of them succeed, the only consolation for us is we usually come off best. Hope this isn't too far off topic and has enlightened you somewhat Regards Dave Swindell ---------------------------------------------------------------------------- 8) From JRKutina@webtv.net (John Kutina) Subject Etched brass railings What is the best way to affix brass railings to resin hulls - 1'160 scale Thank you. Regards, John Kutina ---------------------------------------------------------------------------- 9) From "Allan and Crystal Plumb" Subject Re Sub prop - this way or that way? OK, then, another question. Would a Sturgeon (specifically, USS Lapon) have had the "vertical stabilizers" (not rudders) that are depicted in the Yankee Modelworks kit, in 1974-77-ish? None of the pictures I found from that period seemed to show them, but it would require a drydock photo. Thanks again. Allan Plumb ---------------------------------------------------------------------------- TRADERS, ANNOUNCEMENTS & NOTICEBOARD ---------------------------------------------------------------------------- 1) From "Poutre, Joseph A" Subject Announcing, officially, finally, the Ship Kit Review list version 6.4!! Thanks to many new contributors and much, much work by long-time SMMLie David Wells, the online Ship Kit Review list is now at version 6.4, with new manufacturers and new reviews galore! http//www.quuxuum.org/rajens_list/shiprevs.html Joseph Poutre ---------------------------------------------------------------------------- Check out the SMML site for the List Rules, Reviews, Articles, Backissues, Member's models & Reference Pictures at http//smmlonline.com ---------------------------------------------------------------------------- End of Volume