The bollard pull of a tug is the force it exerts at zero forward speed, in calm water conditions, with the engine working at its full power 100% mcr. Select the right location of where the bollard will be located 2. The dnv bp test procedure is therein considered to be one of the better ones. R ule c ha nge n o t i c e 2014 rule change notice 2014 the effective date of each technical change since 1993 is shown in parenthesis at the end of the.
They are a simple and costeffective way to fulfill mooring requirements and safely secure vessels alongside jetties, berths, wharves and dolphins in ports and harbors. Bollard pull tests sometimes are performed after major engine overhauls. Almost always, a test involves affixing a line to a shorebased bollard and ramping the rpms of the engine to full throttle, typically in ahead and astern conditions. Feb 20, 2017 bollard pull test performed in february 2017, setubal, portugal. Upon activation of the dpv, the propeller spins in dead water, and thrust is 100%. Bollard pull testing becoming standard for newly classed tugs. Bollard pull joint industry project partners, marin. Summarizing the below requirements, practical bollard pull trials need to be. It is calculated using the established holtrop and mennen formula 2. International standard for bollard pull trials v1 2019. Bollard pull certification procedures guidance information, 1992 4. Gives 4 different methods to calculate the required bollard pull. There are few bollard pull procedures available in open literature.
Study on the procedure to obtain an attainable speed in pack. Bollard pull is the most commonly used measure of shipassist tugs performance which have propellers optimized for maximum thrust at close to zero speed. Pdf guidelines for certification of bollard pull engr. Sustained bollard pull is the mean val ue of the pull during a 5 minutes test. Instead, the bollard will simply move slightly towards the hydraulic ram. Theoretical and experimental measurements of bollard pull. Purpose of procedure the purpose of the procedure is to ensure consistency of methodology and the acquisition of correct results for the propulsion test and its special cases bollard pull and trawl pull test bollard pull is the static force exerted by a. Zahalka, association of hanseatic marine underwriters bollard pull is, the tractive force of a tug, expressed in metric tonnes t or kn. What is bollard pull test and requirements for the bollard pull test bollard pull is the static force exerted by a ship on a fixed tow line at zero speed. It is defined as the force in tons or kilonewtons kn exerted by a vessel under full power, on a shoremounted bollard through a towline, commonly measured in a practical test but sometimes simulated under test conditions that include calm water, no tide, level trim, and sufficient depth and side. The safe working load of the test equipment, fittings and any connection points ashore shall be at least 10% in excess of the designed maximum continuous static bollard pull of the vessel. Test procedure bollard pull tests should be carried out under similar conditions to facilitate comparison with results obtained at different testing establishments. This is contained in the sheet named empirical formula.
We would like to show you a description here but the site wont allow us. It rigorously calculates all the forces on the vessel, viz. The vessel is then held at full rpms for between 1 and 10 minutes. Bollard pull calculator for ships excel engine boat. In 1961 the bsra issued their code of procedures for bollard trials of tugs. Trawl pull is a force exerted by a ship on a tow line at speed in another words bollard pull is the maximum pulling capacity of a tug that can exert. Ittc recommended procedures and guidelines propulsionbollard pull test. In 2014 marin evaluated a number of trial procedures and found large. The following testing procedures should be adhered to. Therefore, the bollard test holds the test article stationary in the water to achieve the highest slip values, and thus the highest thrust. A drop in dnvgl witnessed load cell measures the load placed upon a bollard under test. The first method is based on dnv rules for marine operations.
Practical bollard pull tests under simplified conditions are conducted for human powered vehicles. Bollard pull is a conventional measure of the pulling or towing power of a watercraft. What is bollard pull test and requirements for the bollard. A spreadsheet to calculate the required bollard pull to tow a barge. Apr 20, 2020 bollard pull values may be achieved in one of two ways by simulation or by practical trial.
It provides bollard pull for different weather conditions. Tow speed and bollard pull analysis project example. Tug owners whose tugs have been tested usually provide a copyof the certificate attesting to the bollard pull figure. The bollard pull test should be held in a location of reasonably sheltered from wind, current, tide and wave. International standard for bollard pull trials 2019 pdf marin.
This figure is not accurately determinable by mathematical methods, therefore it must be evaluated for each tug by a bollard pull test. R ule c ha nge n o t i c e 2014 rule change notice 2014 the effective date of each technical change since 1993 is shown in parenthesis at the end of the subsectionparagraph titles within the text of each part. The bollardscan tm is a unique way to establish the reliability of the bollard and its foundation. Bollard pull, like horsepower, is a selling point for tugs and is sometimes overstated. If the readings are recorded at 30 seconds intervals, sustained bollard pull is the mean value of these readings during a 5 minutes test. The capacity of tugs is measured by their rated bollard pull. Maximum bollard pull is achieved with the cable right astern, rudders amidships and a further reduction in bollard pull must be allowed for should the angle of the cable lead other than right astern. As a result, it may be possible to repair the bollard and its fixing into the quayside rather than allowing the pull test to inflict further damage which may make repair impossible. Whats really driving the increase in bollard pull testing is the spread of shoreside and offshore liquefied natural gas lng facilities. Following the success of bollard pull calculator for barges. The bollard pull certificate plays an important role in the sale and delivery. The bollard pull certificate plays an important role in the delivery and commercial deployment of tugs. The bollard test can be done in a test tank of any size, but very small containers may set up a circular flow which can give an inaccurate force reading.
Apr 14, 2020 the bollard pull certificate plays an important role in the delivery and commercial deployment of tugs. However, the term bollard pull has developed three different meanings, and it is important to know which intended meaning is being used. This is contained in the sheet named bollard pull dnv. International standard for bollard pull trials download. Pdf reenactment of a bollard pull test for a double propeller. The report presents the used input data and a full report of the analysis. The following guidance notes apply to the bollard pull test of any towing vessel which the surveyor is requested to approve or attend. It was possible to fudge figures by recording only momentary surges maximum bollard pull rather than sustained bollard pull readings over intervals of five minutes, 10 minutes or any other period of time. And whether it still meets the design requirements of the structure. Hold the bollard in place and using a hammer drill, drill one 120mm deep hole into the ground 3. Bollard pull test procedure free download as word doc. Various aspects of bollard pull tests and analysis of test. Bollard pull is the static force exerted by a tug at zero speed on a fixed line. Three remote cameras record the entire bollard load testing procedure, whilst lasers are targeted at the bollard to detect any microscopic movement.
Ships requiring high bollard pull can be fitted with a nozzle, which increases thrust by up to 2040% compared to open propellers. Welcome to the bollard pull calculator for barges rev 02. The methodology that was developed inhouse is based on the transmission of vibration and sound through the structure allowing us to pinpoint any errors. Hold the bolt, hammer into the ground and tighten with a 18mm socket. Detailed information is available in the anchor handling manual. The actual bollard pull trail is carried as follows. Tug and tows a practical safety and operational guide i 3 chapter 8 towing operations 30 bollard pull bp 30 bp calculation 31 pivot point 32 position of tug and interaction 33 girting, girding or tripping ggt 36 gobgog wire or rope 40 emergency quick release systems for towline 42 the effect of wind 42 the effect of current 42. Note that according to the vmo rules the bollard pull certificate and the test.
This study focuses in simulating a bollard pull of a specific tugboat and comparing the results. Actual bollard pull can only be measured in full scale, and is performed during socalled bollard pull trials. While the bollard pull test has been around for many decades, recent changes in technique, technology and datalogging allow engineering. Bollard pull jip launches international standard for bollard. The excel sheet provides four different methods for calculations. Tow speed and bollard pull analysis example project page date.
Steerprop ltd bollard pull trial code by marine mega. This is particularly because, in the event that a pull test results in damage to a bollard for example where a bollard is pulled free of the quayside, it will not be launched by the elastic tension of the rope since none is present. The purpose of the procedure is to ensure consistency of methodology and the acquisition of correct results for the propulsion test and its special cases bollard pull and trawl pull test bollard pull is the static force exerted by a ship on a fixed towline at zero speed. International standard for bollard pull trials download vessel. Marine bollards come in a range of design profiles, sizes and mooring line capacities to suit all mooring operations. Operation of the apparatus 10 will now be described. The second method is using industry standard opl guidelines for barge.
Bollard pull a hydrocomp technical report report 110 overview bollard pull is a term often used to describe the pulling capability of towing vessels. Trawl pull is a force exerted by a ship on a towline at speed. Ad practical trial tests involve suspending a strain gauge on a marine cable that is attached on one end to an immovable object and on the other to the test craft. Pdf use of cfd simulations is an affordable and trustworthy way of. Bollard pull is a direct measurement of the ability of the vehicle to pull on a cable. Values provided by manufacturers can vary due to lack of standards for testing. Download international standard for bollard pull trials the document can be downloaded here. Proposed test program should be submitted prior to the testing. Bollard pull test performed in february 2017, setubal, portugal. Various aspects of bollard pull tests and analysis of test results. The propulsion test procedure addresses model scale only and does not consider ex trapolation and full scale prediction. International standard for bollard pull trials page 4 31 1 definitions 1. Tow speed and bollard pull analysis project example project. Jan 20, 2010 bollard pull testing also provides a way of avoiding confusion, uncertainty and even exaggeration about the actual horsepower rating of a tugs engines.
For best results we suggest the bollard is placed on a flat. With the ever increasing size of vessels, the time has come to focus and raise the issues that have been experienced with bollard failure, as well as the challenges faced in testing the swl of bollards. To view a demonstration of the bollard load test scale model, click the video on the right. Tugs and tows a practical safety and operations guide. These tests are conducted by certified experts from the basrec team. Welcome to the bollard pull calculator for barges rev 02 what does this excel sheet do. Tahoe benchmark research series test pull bollard 2009 dpv. Bollard pull testing also provides a way of avoiding confusion, uncertainty and even exaggeration about the actual horsepower rating of a tugs engines. To initiate the bollard test, hydraulic ram 22 and load cell 24 are located on trolley 60 between bollards 12. Bollard pull test procedure ships telemetry scribd. Leps 150mton wireless bollard pull test system configuration page 2 of 8 bollard pull test procedure asl shipyard 5. Bollard pull overview international marine consultancy bvba.
To construct and use a bollard test device, a motor is mounted to the bottom of a fulcrum device, often a. This excel sheet helps you calculate the required bollard pull of a tug used for towing a barge the first method is using a simple empirical formula. Request pdf various aspects of bollard pull tests and analysis of test results the static force exerted on a hawser at zero ship speed by a vessel, otherwise known as the bollard pull, is one. Rating is available when the video has been rented. This excel sheet helps you calculate the required bollard pull of a tug used for towing a barge how is the excel sheet organised. Although tugs have been around for a long time, a uniform standard for the conduct, measurement and analysis of a bollard pull trial has so far not been available.
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