# Bollard pull **URL:** \ **Category:** Professional Mariner Forum\ **Created:** [February 3, 2025, 2:19pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760 "2025-02-03T14:19:34Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Gmoney](https://avatars.discourse-cdn.com/v4/letter/g/ee59a6/32.png) [@Gmoney](https://forum.gcaptain.com/u/Gmoney)\ **Post date:** [February 3, 2025, 2:19pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/1 "2025-02-03T14:19:34Z")
I wish there would come a day that all towing vessels use the bollard pull system, I think that when you know this and even the dead- weight of a vessel it’s much easier to use a known vessel as a benchmark or reference when doing a similar job with another vessel if you know this, many vessels have a known bollard pull listed on their vessel profile, a lot of vessels do not. A true 2,400 HP vessel to me would be a set of natural EMD 12 cylinder with open wheels or thereabouts , many vessels listed in the south predomitely listed at 2,400 would be in big trouble if they had the same oil barge making a transit through Hells Gate with 20’ of draft, so to me this has been a long time ignored issue that has just become accepted in the world of towing/work vessels, the ship pilots around the south know exactly what their normal working tugs have for bollard pull ---
**Author:** ![tugsailor](https://avatars.discourse-cdn.com/v4/letter/t/a9adbd/32.png) [@tugsailor](https://forum.gcaptain.com/u/tugsailor)\ **Post date:** [February 3, 2025, 3:34pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/2 "2025-02-03T15:34:04Z")
Very very few of the tugs that I’ve sailed on have Bollard Pull Certificates. Bollard Pull Certificates should definitely be required under Subchapter M. A re-test every five years would be a good idea too. Things can change. It’s an inexpensive test. There is too much liar’s horsepower out there. A big difference too between 15’ draft, 3000hp and two big wheels vs 6’ draft, 3000hp and four small wheels. ---
**Author:** ![ombugge](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/ombugge/32/11217_2.png) [@ombugge](https://forum.gcaptain.com/u/ombugge)\ **Post date:** [February 3, 2025, 4:43pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/3 "2025-02-03T16:43:17Z")
If a tug lacks a Bollard pull Certificate based on a test performed according to guidelines from a major Classification Society, approx. bollard pull can be calculated from the following guidelines: > [@](#): > > As a rules of thumb for an approximately conversion from BHP to “t” of the effective available Bollard Pull the following formulas may apply: > > - Tug equipped with fixed pitch propeller (freewheeling): BHP x 0,9 x 1,10 / 100 = (t) > - Tug equipped with fixed pitch propeller and kort-nozzle: BHP x 0,9 x 1,20 / 100 = (t) > - Tug equipped with controllable pitch propeller(freewheeling): BHP x 0,9 x 1,25/100= (t) > - Tug equipped with controllable pitch propeller and kort-nozzle: BHPx 0,9 x1,40/100 (t) Note; (t) = Metric tonnes > > The resulting values have to be regarded as rough estimates and might be variable, depending on parameters of ship’s construction. Nowadays this applies all the more as there is a variety of different types of propulsion systems which might provide different amounts of Bollard Pull defiant of equal engine performance. Source: [https://www.dieselduck.info/machine/02%20propulsion/2010%20GL%20on%20Bullard%20Pull.pdf](https://www.dieselduck.info/machine/02%20propulsion/2010%20GL%20on%20Bullard%20Pull.pdf) PS\> Rough calculation of required Bollard Pull in case of ship-shaped tow in open waters can be found from page 8 of the same document. ---
**Author:** ![tugsailor](https://avatars.discourse-cdn.com/v4/letter/t/a9adbd/32.png) [@tugsailor](https://forum.gcaptain.com/u/tugsailor)\ **Post date:** [February 3, 2025, 4:51pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/4 "2025-02-03T16:51:43Z")
Thank you for this helpful post. ---
**Author:** ![Gmoney](https://avatars.discourse-cdn.com/v4/letter/g/ee59a6/32.png) [@Gmoney](https://forum.gcaptain.com/u/Gmoney)\ **Post date:** [February 3, 2025, 5:23pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/5 "2025-02-03T17:23:43Z")
Exactly, also a big difference between a heavy tug with 18’- 20’ draft loaded with a pair of 16 645 turbo EMD’s rated at say ~ 4,800 HP or so with big wheels vs maybe a Cummins powered triple screw rated at the same HP, at least in the characteristics anyway, the EMD vessel will crunch creosote pilings just in clutch while the other has to be turning a much higher rpm, and again this is just characteristics and not how the bollard pull number is obtained . Still lots of towing vessels around that are under 100’ and even around 80-85’ that are rated HP wise up there with larger EMD & the 3516 Cats when actually they are nowhere close in harbor work or ocean towing and a little lite in the ass, the heavier tug should always outperform a smaller “inflated HP tug” in towing speed when conditions are where you can still pull except probably in fuel consumption. ---
**Author:** ![tugsailor](https://avatars.discourse-cdn.com/v4/letter/t/a9adbd/32.png) [@tugsailor](https://forum.gcaptain.com/u/tugsailor)\ **Post date:** [February 3, 2025, 6:17pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/6 "2025-02-03T18:17:45Z")
There is also the concept of “power tonnage” a big, heavy, older, lower horsepower tug with fine entry, will outperform a boxy, lighter boat with higher horsepower going into a head sea. ---
**Author:** ![powerabout](https://avatars.discourse-cdn.com/v4/letter/p/43a26b/32.png) [@powerabout](https://forum.gcaptain.com/u/powerabout)\ **Post date:** [February 4, 2025, 2:00am UTC](https://forum.gcaptain.com/t/bollard-pull/71760/7 "2025-02-04T02:00:32Z")
Nothing will change so long as companies are happy to hire them… Just like the dive vessels with 1 crew on the bridge. Just like DP vessels with non classed approved DP systems. What happens in the GOM stays in the GOM ---
**Author:** ![Seattle](https://avatars.discourse-cdn.com/v4/letter/s/cc9497/32.png) [@Seattle](https://forum.gcaptain.com/u/Seattle)\ **Post date:** [February 5, 2025, 6:07pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/8 "2025-02-05T18:07:11Z")
There also is going to be a thrust deduction in the range of you calculation of -5-10% in most scenarios… I have seen vessels with the propellers well below baseline so there is no or very little thrust deduction because it is clean water in and clean water out of propeller vs most scenarios where the thruster is tight up against the hull and skeg and thus as you get the higher HP and more water requirements the efficiency of propeller is diminished a bit… ---
**Author:** ![powerabout](https://avatars.discourse-cdn.com/v4/letter/p/43a26b/32.png) [@powerabout](https://forum.gcaptain.com/u/powerabout)\ **Post date:** [February 7, 2025, 2:16am UTC](https://forum.gcaptain.com/t/bollard-pull/71760/9 "2025-02-07T02:16:27Z")
the other problem with bollard pull is its in static water flow. Who has a tug with the water inrush curve to show you how the pull drops in current or when moving? ---
**Author:** ![ombugge](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/ombugge/32/11217_2.png) [@ombugge](https://forum.gcaptain.com/u/ombugge)\ **Post date:** [February 7, 2025, 12:51pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/10 "2025-02-07T12:51:37Z")
> [@powerabout](#): > > the other problem with bollard pull is its in static water flow. Could that be why it is called a “Static Bollard pull Test”? Static because the test is carried out against a stationary Bollard. The tug makes zero speed above ground when the measurement is recoded. The “water flow” (i.e. current) and wind speed at the time has to be within set limits and direction to get a valid test result. Dynamic Bollard Pull is the actual pull asserted on the towed object via the towline. On modern tugs this is measured at the winch or tow hook in real time while in operation: > **[71.dm-2p-19.05.21.pdf](https://www.kongsberg.com/contentassets/a277d133a39c4d8f9c616d54e2af7f4d/71.dm-2p-19.05.21.pdf)** > > 632.91 KB PS\> For ocean towing operations the MWS may set a max allowed dynamic BP limit, based on the the mean break load of the bridle, or tow connections on the towed unit. Here is some useful info re: bollard pull and capabilities of modern tugs: > **[The evolution of bollard pull (and the benefits it has brought) | Hellenic...](https://www.hellenicshippingnews.com/the-evolution-of-bollard-pull-and-the-benefits-it-has-brought/)** ---
**Author:** ![mrdrew](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/mrdrew/32/987_2.png) [@mrdrew](https://forum.gcaptain.com/u/mrdrew)\ **Post date:** [February 8, 2025, 3:55pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/11 "2025-02-08T15:55:11Z")
I’m not really seeing the question here from the Original Post. “Bollard system?” What exactly is that? Then you mention using dead-weight of a vessel. So I’m going to guess you’re talking about the measurement units. I’ve seen bollard pulls listed in [short tons](https://en.wikipedia.org/wiki/Short_ton), [metric tons](https://en.wikipedia.org/wiki/Tonne), [KIPS](https://en.wikipedia.org/wiki/Kip_(unit)), and [pound-force](https://en.wikipedia.org/wiki/Pound_(force)). Other than converting the units (I’m super lazy and have taken to chatgpt for this one!), the concept is solid I think. There are several variables that let a tug pull more or less on a static object, fluid dynamics of the hull being one of them. We mariners are practical people. Put a line on a bollard, pull like hell, and measure it. It is also a sensible test, something that literally does come up in ship assist. When sailing a ship, everything is static, you get into your line and pull like hell. The tonnage thing you mentioned is another fun barrel of monkeys. Gross Registered Tons, and the standard practice of “[tonnage hatch](https://www.marinelink.com/news/shipbuilding-regulations381432?utm_source=chatgpt.com)” is asinine. But these are the rules we play by, design by, and pay our careers. There are a bunch of seemingly non-nonsensical rules! ---
**Author:** ![ombugge](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/ombugge/32/11217_2.png) [@ombugge](https://forum.gcaptain.com/u/ombugge)\ **Post date:** [February 8, 2025, 5:15pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/12 "2025-02-08T17:15:29Z")
> [@mrdrew](#): > > I’ve seen bollard pulls listed in [short tons](https://en.wikipedia.org/wiki/Short_ton), [metric tons](https://en.wikipedia.org/wiki/Tonne), [KIPS](https://en.wikipedia.org/wiki/Kip_(unit)), and [pound-force](https://en.wikipedia.org/wiki/Pound_(force)). Only Metric tonnes an Kilo Newton force are used as measurement of Bollard Pull internationally. Likewise, GT is the international standard. GRT was discontinued in 1982, except in the US. ---
**Author:** ![Gmoney](https://avatars.discourse-cdn.com/v4/letter/g/ee59a6/32.png) [@Gmoney](https://forum.gcaptain.com/u/Gmoney)\ **Post date:** [February 10, 2025, 2:43pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/13 "2025-02-10T14:43:07Z")
I was speaking just in practical terms, knowing the benefits of a heavier vessel, and remember seeing all the vessel specifics including deadweight in the Lloyds of London ship registry, being a tug guy most of us know the capabilities of a vessel from having worked on the vessel or one very similar , knowing the HP, the reduction gears & ratio, the draft & what the main engines are, HP rating’s are so diluted these days especially in the Gulf region, it’s why I wonder with all the Sub-M & everything else we have to deal with why hasn’t a better system of a tugboats true capabilities adopted other than HP, most of us know just by longevity in the industry.Its usually the lightweight tugs, built cheaper with a lot less steel and smaller higher rpm engines that have a high HP rating that tend to bite off more than they can chew but are good at finesse work, quick handling response & overall good fuel consumption vs an old stud tugboat. ---
**Author:** ![ombugge](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/ombugge/32/11217_2.png) [@ombugge](https://forum.gcaptain.com/u/ombugge)\ **Post date:** [February 10, 2025, 3:01pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/14 "2025-02-10T15:01:21Z")
A correctly performed static bollard pull test, certified by a competent organization (Class, MWS etc.) is the nearest you can get to assess tug capability. That is what has been used worldwide for the last 40 years or more. PS\> I started approving towage operations as MWS in 1974. At that time few towing vessels had BP Certificate. American tugs/OSVs specified their engine power in IHP, not BHP . That gave a bigger number on the spec sheet, by didn’t help on their towing power. ---
**Author:** ![Gmoney](https://avatars.discourse-cdn.com/v4/letter/g/ee59a6/32.png) [@Gmoney](https://forum.gcaptain.com/u/Gmoney)\ **Post date:** [February 10, 2025, 6:14pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/15 "2025-02-10T18:14:37Z")
Looking at multiple towing companies online some list the vessels in a HP class that is way off base of the actual combined engine BHP and even in small print when listing the actual engine BHP at a said RPM than that figure is bumped up a few hundred HP I suppose due to the vessel having Kort nozzles , which doesn’t raise the BHP, just efficiency , some companies had the BP listed in short tons and a few cases of the vessel deadweight was listed. It seems only harbor assist tugs, rig moving vessels & higher HP larger towing vessels that may specifically be used on large heavy tows especially when insured for a large amount and marine surveyors involved,lots of the smaller stuff under a real 3,600 HP that list no BP cert, some of the vessels may be just load line anyway. ---
**Author:** ![Hogsnort](https://avatars.discourse-cdn.com/v4/letter/h/ba8739/32.png) [@Hogsnort](https://forum.gcaptain.com/u/Hogsnort)\ **Post date:** [February 10, 2025, 6:52pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/16 "2025-02-10T18:52:36Z")
Like the salvage tugs of yesteryears. The John Ross. ---
**Author:** ![ombugge](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/ombugge/32/11217_2.png) [@ombugge](https://forum.gcaptain.com/u/ombugge)\ **Post date:** [February 10, 2025, 8:13pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/17 "2025-02-10T20:13:46Z")
> [@Hogsnort](#): > > John Ross. Well know salvage tug Smit Amandla (ex John Ross) is sadly no more. Broken up at Alang in 2023: > **[Iconic ocean-going Emergency Towing Vessel to be retired - defenceWeb](https://www.defenceweb.co.za/sea/sea-sea/iconic-ocean-going-emergency-towing-vessel-to-be-retired/)** > > Having delivered nearly five decades of service to the regional and international maritime industry since she was built in Durban in the 1970s, the iconic ocean-going Emergency Towing Vessel SA Amandla is to be “recycled.” Almost 48 years old, she... SA John Ross with her sister tug Wolraad Woltemade (aka WW, or; “Not John Ross but the other one with the difficult name”) Seen here transferring towline at sea: ![image](https://us1.discourse-cdn.com/flex016/uploads/gcaptain_maritime_forum/original/3X/0/5/0548f8103730554feac7ead2a1b47031c9d3bd61.jpeg) PS\> The WW held the title as the world’s most powerful tug for several years. Listed BP was 220 m.t., while John Ross were listed with a BP of 210 m.t. I inspected both tugs several times and did a memorable tow as MWS on the Argentine J/U-rig “Rio Colorado 1” from Tierra del Fuego to Puerto Madry, Argentina with WW. (In 1985) From Ship Nostalgia (require membership): > [@](#): > > #### [BillH](https://www.shipsnostalgia.com/members/billh.16641/) Registered Joined Oct 10, 2007. 1,574 Posts > > - [Jun 7, 2015](https://www.shipsnostalgia.com/media/comments/674664/) > S. A. WOLRAAD WOLTEMADE > O.N 350736. 2,822g. 275n. 2,055d. 94.65(BB) x 15.85 x 7.519 metres oa. > Two, 16-cyl. 4 S.C.S.A. (380 x 457mm) by Mirrless Blackstone Ltd., Stockport, reduction geared to a single controllable pitch propeller. 19,200 bhp. 210 tons bollard pull. 20 kts. Thwartship thrust 800 bhp. propeller forward. > Fire-fighting salvage tug. > 17.4.1974: Keel laid by Robb Caledon Shipbuilders Ltd., Leith (Yard No. 516), for South African Marine Corporation Ltd., Cape Town. > 15.5.1975: Launched. > 23.4.1976: Completed. > 12.2.1979: Transferred to Stephanotis Ltd., Bermuda, and renamed WOLRAAD WOLTEMAADE. > 8.4.1982: Transferred to Wolraad Woltemade Corp., Panama and transferred to Cape Town registry. (Concern as to possible requisition by British Government for Falklands War). > 1986: Pentow Marine (Pty) Ltd., appointed as managers. > 1995: Vessel and managers acquired by Smit International B. V. Rotterdam. > 1996: Transferred to W. W. Tug (Pty) Ltd., (same managers). > 2000: Transferred to Wolraad Ltd., (same managers). > 2003: Smit International Shipping Investments Second Inc, Panama. > 2008: Smit International Shipping Investment Inc, Panama. > 2010: Renamed ICON, St Vincent & The Grenadines flag. > 14.1.2010: Arrived at Alang for demolition. > 20.1.2010: Work commenced by unspecified breaker. > > S. A. JOHN ROSS > O.N 350744. 2,822g. - n. 2,275d. 94.57(BB) x 15.65 x 9.043 metres oa. > Two, 16-cyl. 4 S.C.S.A. (380 x 457mm) by Mirrless Blackstone Ltd., Stockport, reduction geared to a single controllable pitch propeller. 19,200 bhp. 210 tons bollard pull. 20 kts. Thwartship thrust 800 bhp. propeller forward. > Fire-fighting salvage tug. > 18.3.1974: Keel laid by James Brown & Hamer Ltd., Durban (Yard No. 29), for South African Marine Corporation Ltd., Cape Town. > 25.3.1975: Launched. > 8.11.1976: Completed. > 6.8.1977: Transferred to Allamanda Ltd., Bermuda, and renamed JOHN ROSS at Yokohama. > 1982: Transferred to Cape Town registry. (Concern as to possible requisition by British Government for Falklands War). 17.5.1983: Transferred to John Ross Corp., Panama. > 1986: Pentow Marine (Pty) Ltd., appointed as managers. 1995: Vessel and managers acquired by Smit International B. V. Rotterdam. > 1996: Transferred to J. R. Tug (Pty) Ltd., (same managers). > 2000: Transferred to Pearl Shipping and Navigation Corp., (same managers). > 2003: Smit Dudula Pty Ltd., and renamed SMIT AMANDLA, under S.Africa flag. > 2009: Sold to Smit Amandla Marine Pty Ltd. > 5.2015: Still listed as in service. ---
**Author:** ![Gmoney](https://avatars.discourse-cdn.com/v4/letter/g/ee59a6/32.png) [@Gmoney](https://forum.gcaptain.com/u/Gmoney)\ **Post date:** [February 10, 2025, 9:21pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/18 "2025-02-10T21:21:49Z")
Impressive numbers for any era, did a tow transfer with this vessel last year. > **[PACIFIC\_DUCHESS.pdf](https://www.gob.mx/cms/uploads/attachment/file/487279/PACIFIC_DUCHESS.pdf)** > > 3.03 MB ---
**Author:** ![ombugge](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/ombugge/32/11217_2.png) [@ombugge](https://forum.gcaptain.com/u/ombugge)\ **Post date:** [February 10, 2025, 10:22pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/19 "2025-02-10T22:22:29Z")
I believe the world’s most powerful towing vessel is still the Island Victory: ![image](https://us1.discourse-cdn.com/flex016/uploads/gcaptain_maritime_forum/original/3X/a/9/a9090f430784ea9d3c6b8a35d6a1c967a179c8c2.jpeg) Design: Kongsberg Maritime UT 797 CX. Ship Builder: Vard Brevik/Vard Langsten Delivery: February 2020 Certified Bollard Pull: 477 T Vessel specification: > **[MV ISLAND VICTORY](https://www.islandoffshore.com/vessel/mv-island-victory)** > > Deep Water Installation Vessel Island Victory can show off a bollard pull of 477 tonnes! Equipped with a 250 tonnes offshore crane, two ROVs and a large moon pool, the vessel suitable for both pre-lay of anchor systems, installation of subsea... She took over the title from Normand Samson (ex Far Samson) Bollard Pull: 423 m.t.: ![image](https://us1.discourse-cdn.com/flex016/uploads/gcaptain_maritime_forum/original/3X/b/8/b85c17941e05b93c988e0ad8d6af6592c160d536.jpeg) Photo: [Neil C McBride](https://www.shipspotting.com/photos/gallery?user=27363) > **[Normand Samson - Solstad](https://www.solstad.com/vessel/normand-samson/)** > > Est. reading time: 1 minute [https://www.solstad.com/wp-json/solstad/api/vessel/333/pdf](https://www.solstad.com/wp-json/solstad/api/vessel/333/pdf) ---
**Author:** ![BlackPearl1](https://avatars.discourse-cdn.com/v4/letter/b/898d66/32.png) [@BlackPearl1](https://forum.gcaptain.com/u/BlackPearl1)\ **Post date:** [February 11, 2025, 9:17pm UTC](https://forum.gcaptain.com/t/bollard-pull/71760/20 "2025-02-11T21:17:34Z")
I completely agree about those “tonnages” being asinine. Using deadweight as a factor is also asinine. If only there was a way to discover the DISPLACEMENT! What a breakthrough that would be. [Next page](https://forum.gcaptain.com/t/bollard-pull/71760.md?page=2)