The ultimate guide to shipping and tying logs

Edward Liu
Edward Liu

General Manager

Table of content

This is a guide for log loading and lashing, the operation means and ideas involved can be used for similar products.

1 Cargo stowage

There are two factors for shipping timber, VOLUME STOWAGE FACTOR and WEIGHT STOWAGE FACTOR.

According to the reference stowage factor (s/f) given by the port agent or supercargo, the corresponding pre-allocation chart is made and sent to all parties concerned. Estimate the possible loading volume of the ship and calculate the maximum loading volume (cbm) of the ship by using bale capacity.

2 Preparation and inspection before loading

After accepting the timber transportation task, the ship should carry out the preparation and inspection before loading immediately, which is the key link for safe timber transportation.

  • check whether the timber lashing rigging is intact, the number of insufficient to supplement the complete, the damaged should be repaired, these facilities should be approved by the classification society product quality certificate;
  • check whether the loading and unloading machinery is normal because most of the timber loading and unloading process with the ship crane to complete;
  • check whether the proposed loading timber deck, hatch fence and gangway structure are intact, whether the strength meets the requirements, check the column
  • Check whether the structure of the deck, hatch fender and bulkhead for loading timber is intact and the strength meets the requirements, check whether the column and column base are intact and sufficient, check whether there is damage to the lashing ground order, eye plate, ram’s horn, ventilator shield, etc., and repair the damaged parts and make up for the missing ones;
  • Check whether there is damage to the cargo hold of the ship: bilge plate, hull plate, ribs, reinforcing material, side guard, pipe guard, lower cabin ladder, lashing order ring, etc., and repair the damaged parts. The bilge sewage well should be swept dry and clean, check the bilge water inlet strainer, protect it clean and effective, prevent debris from entering the sewage pipe system;
  • check the cargo hold sewage system: make the pipe system smooth and leak-free, the valve open freely, and equipped with enough power and head of mobile drainage pump (mostly submersible pump), in order to be ready for emergency use when the cargo hold sewage system fails;
  • the captain should ensure that the high side ballast tank discharge valve
  • the master shall ensure that the opening and closing of the high side ballast tank discharge valves are properly recorded in the logbook and the discharge valves shall be properly monitored; to prevent accidental injection of water into these cabinets, which may lead to the risk of ship tilting and deck cargo shifting or ship capsizing.
wood lashing 2

3 Water measurement

After docking, the supercargo accompanies the first officer to do the initial water measurement and calculate the constants, etc. Every day when the work shift is rested, supercargo will do the dipstick together with the first officer, update the W/F according to the data of loading at the quay and the data calculated by doing dipstick, and budget the finished cargo dipstick and stability and strength according to the updated W/F, and update the loading plan at any time until satisfied. In this voyage, 35,056 JAS of timber was actually loaded, 32,818 MT of water gauge data, 0.936 MT/JAS of calculated W/F, 1.09 m of initial stability, 1.06 m of corrected stability, 16.66% of maximum bending moment of strength/permitted bending moment at sea, 18.7% of shear force/permitted shear force at sea, which was in favorable mid-drop condition and fully satisfied the sailing conditions.

4 Cargo handling

In New Zealand, the quality of workers is higher, the concept of time is stronger, experienced, and the loading equipment is more advanced, saving a lot of unnecessary trouble. The timber in New Zealand, which is already sawed, is relatively neat and uniform in the specification, loaded up more regularly, and the loss of cabin is also smaller, causing less damage to the ship, but the following aspects need to be noted in the loading process.

(1) When the loading starts to 8 h, the first mate and supercargo will quickly look at the 6 sides of the water gauge and calculate the cargo tonnage during the coffee time. supercargo will ask for the loading volume of this period from the foreman, how much JAS, and calculate the current accumulation factor W/F according to the weight calculated by the first mate, the loading rate, the estimated time to finish the cargo, and ETD.

(2) When all the large holds are finished, this is a key point, the first officer and supercargo calculate a relatively accurate average W/F to determine the deck cargo weight and quantity, as well as the maximum deck cargo stack height, and at the same time fully calculate the ship stability GMo and deck strength, hatch cover strength many factors, all should be taken into account. At this time, supercargo will work together with the captain and first officer to calculate and finally determine the maximum loading capacity and maximum stacking height of deck cargo and declare the load. When there is a disagreement between the ship and supercargo, the ship has to provide and show reasonable explanation and reason to the cargo owner, charterer and related parties, if the reason is sufficient, then it can be adopted, otherwise, it will lead to the claim of corresponding cargo volume loss.

(3) For loading armor plate cargo, in order to speed up, arrange 4 work shifts to carry out, the loading apparatus is the same as machinery, the ship’s side pays attention to pull up the column in advance, put the lashing chain and side lashing wire. Before loading, the foreman and workers were told about the oil tank measuring hole, ballast water tank measuring hole, important channel door cover, bollard position, oil spill room channel, mast room channel, kerring crane channel, etc., and MARK was painted with yellow paint. a special person was assigned to supervise whether the channel was reserved according to the ship’s requirements, otherwise the workers were made to move the cargo again.

wood lashing1

5 Determination of stability and cross-swing cycle

(1) Rough monitoring method – lifting weight test method. The general situation of stability can be roughly monitored, but the calculation result of this method may deviate from the actual one and the swing cycle is influenced by the degree of cable tightness.

(2) Accurate monitoring method – hitting a row of ballast water method, using the method of hitting a row of side compartment ballast water can be a more accurate determination of stability height. Another in the loading process, in order to better monitor the stability of the situation, we should try to use a variety of methods to observe and test, such as ① often observe the distribution of light and heavy wood in the cabin and on the deck up and down, so as to choose the height of the center of gravity of the goods in the calculation of stability for reference; ② often test the six-sided water measuring tape to calculate the amount of loading, especially before loading the deck cargo must be a more accurate measurement of the actual amount of cargo loaded in the cabin, in order to estimate The maximum weight and height of deck cargo loading; ③ according to the whole voyage consumption of oil and water, comprehensive verification of the stability of the voyage and arrival in port to meet the requirements; ④ in the theoretical calculation of the stability of appropriate consideration of a certain amount of safety margin.

The shakedown test of timber vessels is voluntary and not compulsory for ports and cargo owners. For the safety of the ship, the stability of the ship is better verified. The port and cargo owners are willing to cooperate actively when the shipowner requests to conduct it.

The ship side slackens the ship’s fore and aft mooring cables and prepares the stopwatch. The port foreman directs the workers to hoist a bundle of logs with the kerring crane to stop when it is 3~4 m high on the water when shouting “start”, drop to the water quickly and hoist it up quickly, stop after several times in a row, the ship starts to shake horizontally, measure the time of shaking 3 swings horizontally, that is, the cycle of shaking horizontally, to make several times in a row and take its average. Stand on one side of the bridge, through the door window to see the other side of the railing and the height change of the shore object, determine the swing, which is more accurate than looking at the tiltmeter.

wood lashing

6 Lashing of cargo

All lashings and other supplies should have a breaking strength of not less than 133 kN. These lashing supplies shall have no permanent deformation after being pulled by less than 40% of the breaking strength, and the elongation shall not exceed 4% when pulled by 80% of the breaking strength.

The lashing of special timber vessels can be done by referring to the “lashing plan” on the vessel to determine the rooting and orientation of the lashing and the setting of other lashing equipment. Consider also that each lanyard should go around the deck timber and try to make effective contact with the timber throughout the top of the pile so that the timber can be held down and tied when the lanyard is tightened.

Each lanyard should be equipped with a tightening device or system (e.g., tightening sleeve, rod tightener, pulley combination, etc.). Its placement should be such that it can safely and effectively tighten the device or system. A load of each lanyard is not less than 27 kN for the horizontal part and 16 kN for the vertical part.

In the tying lanyard process, tying equipment should match with the tying lanyard, the strength should be consistent, and should do:

  • with wire rope card for wire joints, the number and size of rope card should be proportional to the diameter of the wire, each joint with at least 4 rope cards, the distance between the best for 15 cm, the clip saddle sitting part of the card in the dynamic load end, U-shaped screw bolt card in the static load end.
  • should be in the wire card before tightening, tie the lanyard as tight as possible, to be tied over the force and then tighten.
  • After the lanyard is tightened and initially tied, the remaining length of the screw or remaining tightening force of the tightening device or system should be not less than half of the total tightening force.

The spacing of the lanyard: If the length of the wood is short, the spacing of the lanyard should be properly adjusted to achieve a minimum of two lanyard restraints per piece of wood. Arch-back lanyard: large timber special ship deck timber cargo height up to eight or nine meters, when loaded to about half of this height, need to add the arch-back lanyard, the arch-back lanyard is a very long wire rope, from one end of the timber stack on one side of the deck eye-ring rooted, pulled around the deck timber to the opposite side of the column cross-wound, and then pulled to the other side of the corresponding column similarly cross-wound, repeat the above method, so that Repeat the above method, so that the wire is in S-shaped direction on the wood, and finally rooted at the appropriate location on the deck. There is no tightening equipment in the middle of the arch-back lanyard, and it should not be tightened, and it can be pressed by itself after loading the remaining timber cargo on it. The lashing supplies of special timber vessels are generally bulky and heavy, and the placement and initial tightening of all kinds of lanyards are beyond the reach of manual workers, so lifting equipment should be used to assist in completing the work.

shipping

7 Safety protection of personnel

Since a large amount of timber cargo is stacked on the deck of timber vessel and the top of timber is uneven, which brings a lot of inconvenience and unsafe factors to the crew’s work and passage, the following aspects need to be noted during loading and sailing.

(1) Provide protective clothing, helmets, spiked boots or spiked set of shoes, lightweight life jackets, safety belts, etc. for the crew.

(2) Since the lumber deck piles are very high, each individual pile needs to be equipped with properly constructed ladders, steps or ramps with ties or handrails at both ends. Piles of ladder-like cargo premises may not install the above ladders but should be equipped with a lanyard or handrail.

(3) During the voyage, if there is no convenient crew passage above and below the deck of the ship for safe access to the necessary operational premises from the dwelling, a safe passage shall be provided above the deck cargo. The safety channel should be equipped with railings and rails of at least 1 m in height, and the vertical spacing of the railings should be no more than 330 mm. wire rope lifelines with tightening devices should be set at the centerline of the ship, and the spacing of the lifeline struts should be moderate. If the timber below the lifeline is not flat, a flatter cargo surface with a width of not less than 600 mm should be set up for passage.

(4) check the cabin on the way down, the cargo hold should be fully ventilated, and measure the content of oxygen in the air at different heights in the cabin to prevent the lack of oxygen in the cargo hold so that people suffocate.

(5) The loading of cargo should not affect the normal use of fire-fighting and life-saving equipment, and the safety protection equipment for personnel should be stored in an easily accessible place.

8 Management during the voyage

(1) The lanyard should be checked and tightened once a day in the first three days after the ship starts, and should be checked and tightened once every two or three days afterwards; it should be checked once a day in bad weather. If you find that the thread of the screw of the tightening sleeve has reached the end and still cannot be tightened or the lashing equipment is damaged, you should re-tie it. All inspection and adjustment work should be recorded in the logbook.

(2) When the ship is swaying during the voyage and working on top of the deck timber cargo, pay attention to the safety, wear nail shoes or shoes with nail sets, wear a helmet, and hold the safety rope and fence by hand when walking.

(3) The captain should avoid potential bad weather and sea conditions when making sailing plans, receive weather forecasts and weather fax charts every day, and keep abreast of weather and sea conditions. When it is unavoidable that bad weather will be encountered, before the arrival of bad weather: should check and reinforce the lashing; to reduce the impact should be properly slowed down and adjusted the course; should adjust the fuel and freshwater to reduce the free liquid level and draft difference to ensure the ship has a safe and stable center height.

(4) Use stopwatch every day, observe the ship’s transverse rocking cycle, calculate the approximate GMo, make sure that you have a good idea, and record it in the logbook.

(5) Timber loading, which is not affected by sunny and rainy days, therefore, there is a lot of sewage in the big cabin, as well as the timber itself contains certain water, so we should constantly monitor the sewage situation in the big cabin and discharge water at any time.

9 Conclusion

The whole process of loading timber ship has more details, pre-matching, stability calculation, declaration of load, including the inventory of lashing wire, chain and other attributes, maintenance, fixed time and position, etc. must be considered in advance, and the ship must develop corresponding cargo transportation management measures for the characteristics of the goods shipped, and make corresponding preparations for the specific conditions of the port of shipment to ensure the safe shipment, storage and delivery of goods.

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