tumblehome hull advantages

0000003058 00000 n While the stealth characteristics of these hull forms make them attractive to the Navy, their sea keeping characteristics have proven to be problematic. So some tumblehome would be a good thing. Extreme conditions are dangerous for any ship, the official said. by ESP Tue Feb 21, 2012 9:05 pm, Post Tumblehome hulls haven't been seen on naval ships in over a century. The Hull - GlobalSecurity.org All ships may face dangerous conditions, he said. Ellyptical tansoms are generally thought to have come into being strictly for pragmatic reasons. W.L.Crothers, McGraw Hill (1997). Thats all for today, thank you so much. Both the French and Russians eventually dropped the hull form. 0 [4], Last edited on 15 February 2023, at 19:34, Learn how and when to remove this template message, "Frank Lloyd Wright Building Conservancy", Traditional Birchbark Canoes Built in the Malecite, Penobscot and Passamaquoddy style, DDG-1000 Zumwalt / DD(X) Multi-Mission Surface Combatant Future Surface Combatant, https://en.wikipedia.org/w/index.php?title=Tumblehome&oldid=1139565021, This page was last edited on 15 February 2023, at 19:34. PRICE CODE 17 18.SECURITY CLASSIFEA- TION CATIONOF REPORT Unclassified SECURITY CLASSIFI-OF THIS PAGE 19. FLARE A flared hull widens out near the gunwales. Unlike most contemporary warshipsor any ships for that matterthe Zumwalt uses a so-called tumblehome hull. The U.S. Navy's Zumwalt-class (DDG-1000) stealth destroyerthe Lyndon B. Johnsonwas able to complete its "builder's trials" at the General Dynamics Bath Iron Works in Maine last week. It existed historically for a wide variety of reasons. It allowed for maximizing a vessel's beam and creating a low center of gravity (by decreasing mass above the waterline), both tending to maximize stability. . For example early IOR era boats have a bulge in their topsides that relates favorably increasing girth and also altering the apparent beam by distorting the hull at the points at which the beam measurement was taken. ", Still another naval analyst said the problem is worse than that: "It is inherently unstable.". ", "The Navy would say it has tested the software thoroughly and knows exactly what it is. by RodeoClown Wed Feb 22, 2012 1:25 am, Post The Navy's Zumwalt-Class 'Stealth' Destroyer Has One Big Problem Experts offer their predictions. The US Navy's Stealth Zumwalt Destroyers: Armed with Hypersonic The Navy is analyzing potential alternative designs now for the cruiser, which is to carry a heavier, more powerful radar and more missiles than the Zumwalt. You know you have been following @TheDreadShips too long when you look at the Mercedes W14 and think, nice tumblehome hull there . Well-modeled double enders are not easy to mould in fiberglass since there was often some tumblehome in the stern making it hard to remove them from a single part mould . 0000003652 00000 n Advantages of hull flare can include improvements in stability, splash and wash suppression, and dockside utility. Navys New Ship Can Operate By Itself for 30 Days, Navy's USS Zumwalt to Fire Hypersonic Missiles, Russia Retires The Hunt for Red October Sub. Righting arm is reduced with increased immersion/increased heel. But the effect will be minimal if the tumblehome you're look at, for styling, is around 5~10degrees. The opposite of tumblehome is flare . Tumblehome designs also have some improvements in seakeeping over a conventional flared design. tumblehome | Boat Design Net "Frankly, the people best qualified to do it are the people already involved in the design and testing of the hull," he said. By the same token, the narrow deck line associated with tumblehome can reduce the initial force needed to start to right an inverted boat however, depending on how the tumblehome is shaped, it can also increase less significant ultimate force required to right the boat. New to this category is the Zhaochang patrol ship, purpose-built for long-distance fisheries enforcement with a new tumblehome hull design and a 30 . The term is also applied to automobile design, where a vehicle's sides taper inward as they go up. "If you're operating a million-watt radar, the question might be: Why invest in this hull in the first place? "The capsize risk for the tumblehome geometry had a greater increase for small increases in KG [center of gravity] than the flared topside geometry." However, there has been a lot of work done. Contents. The Russian Navy, however, did somewhat adopt tumblehome ships. We enjoyed everything about our stay - rented the pontoon boat and fished for a day with a shore lunch that we packed ourselves. For example, I know that. The Electric Warship - IEEE Spectrum Like every design question, it's a matter of trade-offs. Navy Unveils Next-Generation DDG(X) Warship Concept, WI the Imperial Japanese Warships of Operation Ten-Go was ISOT to the Battle of Jutland. 5482 0 obj <>stream (U.S. Navy photo by . My plan is to reign in the design, then make a shipbucket, then make a better 3d model in Rhino 3D (right now its in Sketchup). As such, a tumblehome design will be better armoured or armed than an equally-sized conventional design. Ideally, a boat does not change trim, or roll down or roll out as it heels. The 'tumblehome' hull forms a design in which hull slopes inward from above the waterline. Since the interior walls are straight, the transition takes place in the exterior windows and doors which are wider at the bottom than they are at the top. And why suffer the peril of an inherently instable hull form? Was that part of the reason for late adoption of superfiring turrets, especially in some navies? And tumblehome at the stern is a design feature that most custom builds and even some production boats boast. h2g2 - The Disastrous History of HMS Captain - Edited Entry. The destroyer uses a unique "tumblehome hull design. There's nowhere left to go with the Arleigh Burke design, meaning the service will have to find a new ship to meet . 0000014703 00000 n 0000135757 00000 n At one point the commanding officer of the ship, Captain Andrew Carlson, was told by his second in command that the ship was in Sea State Six but later said it felt as though they were only in Sea State Three, where waves average only 2 to 3 feet. This includes a roof tapering in, and curved window glass. [2] A French yard was contracted to construct the pre-dreadnought battleship Tsesarevich along the lines of France's Jaurguiberry, which was delivered to the Russian Imperial Navy in time for it to fight as Admiral Wilgelm Vitgeft's flagship at the Battle of the Yellow Sea on 10 August 1904. "We feel very confident in the hull form," said Allison Stiller, the deputy assistant secretary of the Navy for ship programs told Defense News in 2007. Tumblehome allows the advantages of a wider boat - stability, water shedding - without the disadvantage of the paddle shaft being pushed way off the boat centerline by the outside gunwale. by ian123 Wed Feb 22, 2012 3:25 pm, Powered by phpBB Forum Software phpBB Limited. The S. A. "I have no doubt they've crunched the numbers as accurately as they can. There are several factors at play when you try to determine whether it's a good or bad thing in a particular case. As mentioned, the case could be made the timber ships of war had tumblehome in order to keep the weight of the heavy guns within the limits of the waterline, to allow the guns to be rolled out and fired even when ships we grappled together in close combat, and due to issues related to timber ship construction (the convex surfaces associated with tumble home meant that the seams were compressed rather than stretched open when exposed to high loads.). The tumblehome has been reintroduced in the 21st century to reduce the radar return of the hull. Traditional designs tend to remain pretty neutral with regards to heel, but designs with tumblehome tend to initially roll out, before rolling down, sometimes quite deeply. ", Syring addressed claims that the ship was in danger in quartering seas waves that come at the ship from behind by saying: "There is a wide range of safe seas on a quartering heading in Sea State Eight.". ", One question the Navy should ask, he said, is: "Why does this question [of doubt] persist? Die Europische Verteidigungsagentur finanziert ein Projekt zur Automatisierung von Luftbetankungsvorgngen. . Touring and expedition canoe hulls need to take lake waves (and moderate whitewater) and still have good hull speed. URANS prediction of roll damping for a ship hull section at shallow Minimize total hull resistance at maximum speed Generate adequate beam to arrange container cells nine-across within the hull Provide protection against deck wetness for containers stowed above the main deck Provide excellent freeboard forward Minimize its metacentric height and therefore maximize its roll period Damp roll motions at high speed On the DDG 1000, with the waves coming at you from behind, when a ship pitches down, it can lose transverse stability as the stern comes out of the water and basically roll over.". The design moves through waves much more easily, and will rarely ride over the top of them. Funny thingI was never attracted to those hull shapes Jeff shared a really interesting discussion of the design and performance aspects of tumblehome. "The standard Navy requirement for stability in ships is a 100-knot wind," he said. The Fora platform includes forum software by XenForo. Forum posts represent the experience, opinion, and view of individual users. The vessel with 14,500 tons is a multi-function class that was built with a primary purpose of naval gunfire support and secondary roles of surface and anti-aircraft warfare. 0000007972 00000 n DDG 1000 Zumwalt Class - Multimission Destroyer - Naval Technology model test | SPE Wenonah Canoe manufactures canoes and paddling accessories for paddle If all the critics are right, this thing is dangerous. The hull and rudder interaction coefficients, thrust deduction factor, inflow velocity to propeller, and inflow velocity to rudder are obtained in large drifting conditions using the measured . 0000009269 00000 n JavaScript is disabled. The tumblehome hull forms a design in which hull slopes inward from above the waterline. Also rented a golf cart - pretty handy to zip down to the store and back. In the era of oared combat ships it was quite common, placing the oar ports as far abeam as possible, allowing maximum possible manpower to be brought to bear. A forum community dedicated to Sailing enthusiasts. Its long, angular "wave-piercing" bow lacks the rising, flared profile of most ships, and is intended to slice through waves as much as ride over them. The problem with that, of course, was reduced seakeeping due to the lower freeboard, and designers spent most of the 1870s and 1880s trying to combine gun turrets and high freeboard. Questions have dogged the design of the Zumwalt's tumblehome hull for years. There's a lot of confidence in designing a conventional hull. The sharply reduced crew size of just 182 promises operational cost savings and instant response, but automated damage control mechanisms coordinated by software remain an unproven option. But the concerns from current surface warfare officers have not persuaded Navy leaders to re-evaluate their position, he said. However, France in particular promoted the design, advocating it to reduce the weight of the superstructure and increase seaworthiness by creating greater freeboard. The ship's topsides are streamlined and free of clutter, and even the two 155mm guns disappear into their own angular housings. Press J to jump to the feed. If you find this post is interesting, do not forget to like, comment in the end this post. Can the Navy's $12 Billion Stealth Destroyer Stay Afloat? - The Daily Beast in my opinion, a tumblehome hull is always inferior to a flaring hull in seakeeping and stability (for reasons described . Center Console Boats with Clever Transom Designs The ship's centre of gravity is usually lower, decreasing the angle of roll, and so making the ship more comfortable. Copyright 2021 - Forces Project - All Right Reserved. 0000009884 00000 n "Those folks are genuinely interested and passionate," he said. The Navy's F-22: Why the Stealth Zumwalt Destroyers Failed The early skin kayaks of the Arctic relied on wooden ribs and longitudinal stringers for form. "The last thing I'd be doing right now is to award ship-construction contracts if the technical people have problems.". Officials from both contractors deferred to the Navy when asked about the design. ? Tumblehome - C-Forum Study on nonlinear heave and pitch motions of conventional and With the advent of gunpowder, extreme tumblehome also increased the effective thickness of the hull versus flat horizontal trajectory gunfire (as any given width material grows effectively "thicker" as it is tilted towards the horizontal) and increased the likelihood of a shell striking the hull being deflectedmuch the same reasons that later tank armour became sloped. 0000018739 00000 n Norman Friedman, a naval consultant and author of a series of design histories on naval warships, said, "This thing has a very good potential for causing a lot of problems. A tumblehome curve can make it easier for a paddler to reach over the side and get a proper vertical forward stroke. Since the center of gravity does not move, this in effect means that a plot of the stability curve changes shape gently and without humps as the boat is rotated through a full cycle. DDG 1000 has a 'tumblehome' hull form, a design in which hull slopes inward from above the waterline. What do all you experts have to say? Shouldered tumblehome, in which the hull flares out to a "shoulder" of maximum beam a few inches below the sheer line and then sharply recurves in to the gunwales, offers the advantages of a flared hull in that it sheds water well and has good secondary stability, but reduces the width at the gunwales. Model of a French 74-gun ship from 1755 showing tumblehome as its hull narrows rising to the upper deck. he asked. Discussion of all things WhiteWater Canoe related, Moderators: kenneth, sbroam, TheKrikkitWars, Mike W., Sir Adam, KNeal, PAC, adamin, Post This means that a tumblehome design is much more vulnerable to capsize. Flare Flare shaped canoes feature sides that flare outwards from the waterline to the gunnels. Flare Another retired senior naval officer expressed concern that, with an all-new hull form, the modeling technologies used to predict at-sea performance may be flawed. Basically when it's pushed from astern there's not much to catch the bows being pushed pitch down. As noted, much has been made of the ship's tumblehome hull design and its perceived lack of stability. The Zumwalt reportedly quickly rights itself in rough waters, faster than other designs. Another advantage of a tumblehome is that enemy warships are kept as far away as possible, due to the broad distance covered by the ship's convex sides. According to Downey, as quoted by USNI, tumblehome is the only method the best naval architects and designers could produce the least bow wake, stern wake and reduce radar cross section. Even among many critics, there are those familiar with the Navy team leading the DDG 1000 effort who don't doubt the sincerity of the Navy's engineers. The senior surface warfare officer also supported the design team. I feel like you would want to slope the armour and reduce the flat deck area by as much as possible, both to reduce plunging fire damage. As multi-mission stealth ships with a focus on land attack, this ship is larger than Ticonderoga-class cruisers. Zumwalt-class destroyers feature a state-of-the-art electric propulsion system, wave-piercing tumblehome hull, stealth design and is equipped with Liked by Jeff Jordan startxref And the Navy shouldn't base CG(X) on the Zumwalt hull "until we get some experience with DDG 1000, or get a larger model where we can verify the performance of the hull," he said. These two factors mean that more weight can be devoted to the ship's main belt armour, or to armament. ", "These retired folks don't have the data that I have," Syring said. It also had limited reserve buoyancy - by reducing the hull volume above the waterline, there was little extra volume to keep it afloat when compartments below the waterline flooded. 0000003522 00000 n by eddyhops Wed Feb 22, 2012 2:35 am, Post But will the actual ship follow the models? Answers must be in-depth and comprehensive, or they will be removed. In short, this is the Zumwalt class with all of the ability and a significant achievement that brings it one step closer to being able to carry out operational missions, no matter how limited, in more challenging situations. Some people have criticized the Zumwalt tumblehome hull, because it lacks these features. Whatever they shifted or removed did not affect the stability of the hull form.". Looking for both advantages and disadvantages please. "Additionally, the aft tumblehome extension makes for great storage that runs deep into the transom. What Is a Tumblehome? (with pictures) - Wiki Motors You are using an out of date browser. What is a Boat Chine and What are the Differences? Tumblehome designs have some major advantages for battleship designs. This design features the famous Carolina flare, broken shear and tumblehome that is sure to turn heads. xV}TSI&|H*B E41QJ #t8w]pJS\a U ~Tli _[KUt=g{M`[{?ws= E% E lhe.x@0l/` GEAk930w;:UJ5OQn"XZXW6P ", "What I'm trying to find out is what speeds do we want to avoid in those sea states," Syring said. The RN and USN couldn't accept a ship that didn't cope well with storms due to their need to work in the stormy North Atlantic. That curvature made the hull stronger than what a slab side would. "They've gone to enormous lengths in order to be stealthy. The magnitudes of the motion transfer functions increase as the wave slope increased. The Navy May Use One Hull Design To Replace Its Cruisers - The Drive Were slings considered less "prestigious" than bows? I think that is my favorite part, although rolling up in my Option with about 4 inches of water is pretty nice, too. 0000012221 00000 n The tumblehome will affect rolling if you think the boat will roll lots or wish to use tumblehome to reduce rolling. Could you elaborate as to tumblehome liabilities in these areas? 0000140477 00000 n Tumblehome is a term describing a hull which grows narrower above the waterline than its beam.The opposite of tumblehome is flare.. Can someone post a picture or describe tumble home. Essentially, no one has ever been to sea on a full-sized ship of this type. Technological advances have improved the capability of modern destroyers culminating in the Arleigh Burke (DDG 51) class replacing the older Charles F. Adams and Farragut class guided missile destroyers. The industry source said that throughout the design process, "decisions about systems to leave or replace, [changes in] weight and displacement were a continuing consideration. Now its captain is speaking out about how it handles high seas. I seem to recall that for a brief time certain rating rules measured beam on deck, and tumblehome was a way to add 'unmeasured/unpenalized' beam. New comments cannot be posted and votes cannot be cast. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features Press Copyright Contact us Creators . They trained their successors, who in turn used the design styles they were taught. 0000010626 00000 n Thanks for all the answers, I got the idea that Tumblehomes were bad from the wikipedia article on the subject and I now see that it was very flawed. It cannot be denied that the USS Zumwalt, with its knifelike bow, is more stable in stormy weather than other destroyers and cruisers. ", But he still harbors doubts. ", "Some people have argued for years that you should have incrementally taken the propulsion, the gun, etc., and put these into later iterations of [DDG 51 Arleigh Burke-class destroyers] to get a better understanding of how they operate," said the retired senior line officer. While others that rise out of the water are said to roll out. Go easy on me, Newbie hereConcave Hull design question Design Competition: Multi-Purpose E-Foiler.