# Parametric Rolling Part 2 **URL:** \ **Category:** Professional Mariner Forum\ **Created:** [December 8, 2020, 2:08pm UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655 "2020-12-08T14:08:31Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Kennebec\_Captain](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/kennebec_captain/32/13_2.png) [@Kennebec\_Captain](https://forum.gcaptain.com/u/Kennebec_Captain)\ **Post date:** [December 8, 2020, 2:08pm UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/1 "2020-12-08T14:08:31Z")
Doesn’t look like the One Apus was case of parametric rolling - so thought a new thread was in order. It pays to be wary of the site Marine Insight. The quality varies. For example in the article about [Parametric Rolling the Marine Insight post s](https://www.marineinsight.com/marine-safety/what-is-parametric-rolling-in-container-ships/)ays this: > The difference is that “Parametric Rolling” is a type of movement that is experienced only on **Container Ships**. That’s just flat out wrong. [An older thread on parametric rolling here:](https://forum.gcaptain.com/t/parametric-rolling/47542) [https://www.steamshipmutual.com/ParametricRoll.pdf](https://www.steamshipmutual.com/ParametricRoll.pdf) Case mentioned in above article is the APL China - Oct 1998. Parametric rolling was not understood by the maritime community at the time. ---
**Author:** ![Kennebec\_Captain](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/kennebec_captain/32/13_2.png) [@Kennebec\_Captain](https://forum.gcaptain.com/u/Kennebec_Captain)\ **Post date:** [December 8, 2020, 2:44pm UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/2 "2020-12-08T14:44:52Z")
[http://www.maths.lth.se/matstat/staff/georg/HuaPalmquistLindgrenSTAB2006.pdf](http://www.maths.lth.se/matstat/staff/georg/HuaPalmquistLindgrenSTAB2006.pdf) > Between February 1 and 4, 2004, the PCTC AIDA experienced head sea parametric rolling at > five different occasions, which was recorded by an onboard operational decision support system. ---
**Author:** ![CROSSBOLT](https://avatars.discourse-cdn.com/v4/letter/c/53a042/32.png) [@CROSSBOLT](https://forum.gcaptain.com/u/CROSSBOLT)\ **Post date:** [December 8, 2020, 11:17pm UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/3 "2020-12-08T23:17:10Z")
Greatly detailed articles beyond my understanding! Does any other ship-type use the hull shape of the container ships? ---
**Author:** ![Klaveness](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/klaveness/32/7001_2.png) [@Klaveness](https://forum.gcaptain.com/u/Klaveness)\ **Post date:** [December 9, 2020, 6:28am UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/4 "2020-12-09T06:28:28Z")
> [@CROSSBOLT](#): > > Does any other ship-type use the hull shape of the container ships? Those characteristics turn up whenever speed / length is more important than dwt / build cost, while deck space is valuable. This doesn’t apply to a lot of big boats, though. KC mentioned PCTCs, which seems logical. The other example that springs to mind is aircraft carriers; does anyone know if they’re prone to parametric rolling? > [@Kennebec\_Captain](#): > > The quality varies. Indeed, this sentence is indicative of someone who doesn’t really get the whole object through water thing: > [@Marine Insight](#): > > The new container ships coming to the market have large bow flare and wide beam to decrease the frictional resistance which is generated when the ship fore end passes through the water, making it streamlined with the hull. ---
**Author:** ![Kennebec\_Captain](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/kennebec_captain/32/13_2.png) [@Kennebec\_Captain](https://forum.gcaptain.com/u/Kennebec_Captain)\ **Post date:** [December 9, 2020, 11:00am UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/5 "2020-12-09T11:00:34Z")
Good post from Old Salt Blog. Rick Spilman is: _“a writer, a sailor, **a naval architect,** a student of maritime history, a videographer and a multimedia designer,”_ > **[What Happened on the Container Ship ONE Apus? A Glimpse at Parametric Rolling](http://www.oldsaltblog.com/2020/12/what-happened-on-the-container-ship-one-apus-a-glimpse-at-parametric-rolling/)** > > Last week, the container ship ONE Apus lost or had damaged over 1,900 containers in a storm in the Pacific. The lost or damaged containers representing close to 25% of the ship’s cargo. The casualty represents more containers than are … Continue... Some good links at Spilman’s post. > **[Container Ships Motion in a Parametric Roll - How To Avoid Adverse Affects?](http://shipsbusiness.com/parametric.html)** Technical but more understandable than the more academic articles. [Current Status of the 2nd Generation of Intact Stability: Investigation of the Pure Loss of Stability and Parametric Roll Mode](https://www.joet.org/journal/view.php?doi=10.26748/KSOE.2019.047) ---
**Author:** ![Kennebec\_Captain](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/kennebec_captain/32/13_2.png) [@Kennebec\_Captain](https://forum.gcaptain.com/u/Kennebec_Captain)\ **Post date:** [December 19, 2020, 4:21pm UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/6 "2020-12-19T16:21:38Z")
Here is the story of the APL China > **[Monsterwellen](https://www.outsideonline.com/1922111/monsterwellen)** > > Every hour of every day, behemoth container ships cruise the highways of ocean commerce, loaded with stereos and lobster and plastic air fresheners. And during the winter storm season, massive waves from out of nowhere can wreck these arks of global... ---
**Author:** ![Heiwa](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/heiwa/32/1054_2.png) [@Heiwa](https://forum.gcaptain.com/u/Heiwa)\ **Post date:** [December 20, 2020, 8:15am UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/7 "2020-12-20T08:15:59Z")
A ship heels, when the transverse weights/buoyancy forces are off the center line, CL. An inclining experiment in still water to decide the KG of a ship is one example. You move a known weight at CL to the side and the ship heels a certain angle due a heeling moment applied. It doesn’t roll. When you move the weight back to CL, the angle of heel becomes 0 again. Similar heeling, that can be thought of as rolling, may occur in a swell (ocean interface water/air is wavy) passed at 45°, when the buoyancy forces P&S become uneven, e.g. the bow flare is immersed more on one side, while the stern is immersed more on the other side and a heeling/yawing moment due to uneven buoyancy above/below waterline will develop – the ship heels and yaws. The sudden heel can be \>40°, which some people call parametric (?) rolling. The ship may also yaw (twist, change course) \>10° at the same time. Anyone who has been at sea has experienced it. Only way to avoid it is to slow down and/or change course. It is called good seaman ship! ---
**Author:** ![Tupsis](https://avatars.discourse-cdn.com/v4/letter/t/e9a140/32.png) [@Tupsis](https://forum.gcaptain.com/u/Tupsis)\ **Post date:** [December 20, 2020, 8:23am UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/8 "2020-12-20T08:23:30Z")
Please disregard the terminology and pay attention to the footage. [![](https://us1.discourse-cdn.com/flex016/uploads/gcaptain_maritime_forum/original/3X/6/d/6d3815f9ef187c939ca76225c1820c10d0432e5c.jpeg "Parametric roll") ](https://www.youtube.com/watch?v=ewqaRMGv2mE) ---
**Author:** ![Klaveness](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/klaveness/32/7001_2.png) [@Klaveness](https://forum.gcaptain.com/u/Klaveness)\ **Post date:** [December 20, 2020, 9:30am UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/9 "2020-12-20T09:30:01Z")
That’s a pretty dramatic example, heightened by the choice of HeroApproachesPiratesThroughStorm.mp3 ---
**Author:** ![Heiwa](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/heiwa/32/1054_2.png) [@Heiwa](https://forum.gcaptain.com/u/Heiwa)\ **Post date:** [December 20, 2020, 9:45am UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/10 "2020-12-20T09:45:14Z")
Maybe the crew has headphones at sea and listens to trash rock to pass the time? ---
**Author:** ![Tupsis](https://avatars.discourse-cdn.com/v4/letter/t/e9a140/32.png) [@Tupsis](https://forum.gcaptain.com/u/Tupsis)\ **Post date:** [December 20, 2020, 9:32pm UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/11 "2020-12-20T21:32:36Z")
> [@Klaveness](#): > > That’s a pretty dramatic example… It’s a demonstration where the parameters are selected to produce the worst possible case. Nonetheless, the rolling angles increase within a few cycles. Can imagine such phenomenon coming as a surprise to the crew. ---
**Author:** ![Kennebec\_Captain](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/kennebec_captain/32/13_2.png) [@Kennebec\_Captain](https://forum.gcaptain.com/u/Kennebec_Captain)\ **Post date:** [December 20, 2020, 9:47pm UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/12 "2020-12-20T21:47:47Z")
> [@Tupsis](#): > > . Can imagine such phenomenon coming as a surprise to the crew. Not just a surprise. A big sea boarding from ahead or a series of synchronous rolls from a quartering sea might come unexpectedly but at least it’s easy to see and understand what’s happening. Parametric rolling can be both unexpected and inexplicable. The master of the APL China said it was as if the devil had sized the ship. From Outside Online Monsterwellen > A seasoned mariner from India who’d been captaining container ships for 15 years, Guard was an exceptionally expert witness, France said. In a deposition lasting three of the six days that the _China_ spent in Seattle, Guard reconstructed the voyage day by day, then, as the time of the disaster neared, hour by hour, then minute by minute, corroborating his testimony with entries in the logbook. While that testimony isn’t in the public record, one very telling quote from it is. Just before the containers began to fall, the ship had suddenly become “uncontrollable,” Guard testified, “as if there were a devil in it.” > The (wave tank) experiment proved that if Parvez Guard had done everything he’d been trained to do, if he’d heaved to and decelerated and the engines had not yet failed, the accident still would have occurred. And ironically, if Guard had not done what he’d been trained to do if he’d maintained his speed, for instance disaster might never have struck. ---
**Author:** ![Kennebec\_Captain](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/kennebec_captain/32/13_2.png) [@Kennebec\_Captain](https://forum.gcaptain.com/u/Kennebec_Captain)\ **Post date:** [May 2, 2021, 12:37pm UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/13 "2021-05-02T12:37:18Z")
A post was split to a new topic: [Marine Insight Post on Parametric Rolling](https://forum.gcaptain.com/t/marine-insight-post-on-parametric-rolling/59354) ---
**Author:** ![Kennebec\_Captain](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/kennebec_captain/32/13_2.png) [@Kennebec\_Captain](https://forum.gcaptain.com/u/Kennebec_Captain)\ **Post date:** [May 2, 2021, 12:36pm UTC](https://forum.gcaptain.com/t/parametric-rolling-part-2/57655/14 "2021-05-02T12:36:46Z")