6.6

Chapter 6

6.6 Salvage of floating packaged goods

Salvage of floating drums
Method	Salvage by collection nets
Application	Mainly floating drums containing certain short-chain hydrocarbons, alcohols, ethers, ketones, amines, acetates, aldehydes. Also other types of floating packages containing dangerous goods.
Description	Small packages (like drums) floating on the water surface can most easily be salvaged by a special heavy-duty designed collection nets.		Figure 6 - 34 Collection bag nets for salvage of packaged dangerous goods on the water surface.
	Figure 6 - 35 The net device should be manoeuvred with appropriate considerations of safety precautions as the package may be damaged during the operation.	Picture source: CEDRE
	Figure 6 - 36 There are also specially constructed, more sophisticated and robust systems for salvage of items on the sea surface like this “Sealift”.	Picture source: SMV Engineering A.S., Norway
Limitations	Operational wave height maximum 2 m.

Salvage of floating freight containers
Method Lifting by crane.
Application A floating container may be recovered on board a salvage ship by lifting it to the stern using slings attached to the corners of the container.
Description Large containers, e.g. freight containers, must be salvaged by means of arrangements which are adjusted from case to case with regard to the circumstances and to the available salvage equipment. Specially designed slings for hooking on freight containers (cf. Figure 6 - 37) should be available on board the salvage vessel. These slings are fitted with two hooks (ABK or CROSBY) having a carrying capacity of at least 20 tonnes (each sling has a length 5 metres and a breaking point of 50 tons). Procedure • If possible start to recover part of the container’s contents already when it is still waterlogged. • Clear the deck of the salvage vessel and prepare for use of personal protective gear if necessary. • Reel out 100 m wire cable with attached buoys to make it float. Carry four slings by a workboat to the floating container. • Handled the slings one by one at each of the container corners held by a buoy in the water. • Hook the slings onto the corners. Use lower corners if they are judged to be of better strength. • Manoeuvre the salvage vessel in such a position as to lift the container in the safest way (if possible with the container doors facing the vessel). • Start winching as soon as the container is raised by a wave. • Control the cable tension during lifting (a 20-foot container ¾ filled with water has a weight of nearly 30 tons). • If necessary (and if possible) puncture and drain the container at the start of the lifting operation. • Fasten the container as soon as it is keeping balance on the vessel’s deck. It can later be moved to a safer place.
Picture source: CEDRE Figure 6 - 37	Picture source: CEDRE Figure 6 - 38	Picture source: IMO Figure 6 - 39
Limitations A salvage vessel with heavy lifting capacity must be available for the operation as the weight of the container may increase considerably due to penetration of water and mud. The weather must be calm enough to allow attaching the container to a crane hook. No attempts should be made to recover the container if its contents is unknown (it should however be buoyed).

Salvage of floating freight containers
Method	Towing to a safe haven.
Application	A towline is attached to one or more of the container corners and the container is towed to a haven where it can be safely taken care of.
Description	Experience has shown that a floating freight container during a towing operation (cf. Annex 3, accident Perintis) may be accidentally lost and unable to be found again. It is therefore important prior to the towage operation to equip the container with
	1)	a large buoyant device (floatation boom or collar) with buoyancy enough to keep the container afloat, and
	2)	a tracing device e.g. radio transmitter, transponder, radar reflector or optical blinker.
	It is recommended that four propylene ropes are attached asymmetrically to the corners of one of the short sides of the container. Two by two of the ropes should be of equal length. The length of two of the ropes should be double or threefold the length of the shorter ones. The ropes of equal lengths should be attached in the corners of the same perpendicular. In such a way one of the edges of the short side of the container will plough through the water like the stem of a ship. The resistance of the water during such a towage is considerably reduced compared to if the ropes would be attached in a symmetric way to the container. The ropes could be difficult to attach even in a slight sea swell and sometimes it might be judged to be enough with two hooks (one submerged) at each end of a vertical edge. If the sea is too rough for a fastening the hook on a submerged corner it might be sufficient to attach a single rope to one of the available hooks above the water surface.
Limitations	Towage of a container with potentially hazardous leaking content must be planned carefully in order to avoid vulnerable coastal sites. The safe haven for the container as well as all safety precautions must be carefully selected and planned with appropriate regard to the operation against the container.