Salvage construction and method for salvaging a shipwreck or the like

The invention relates to a salvage construction for salvaging a shipwreck or the like, which salvage construction comprises a portal with legs, which legs serve for positioning at both sides of the shipwreck that is to be salvaged. The invention also relates to a method for salvaging such a shipwreck, using the salvage construction referred to above .

Especially in the case of large and/or very heavy shipwrecks, the problems arising when the shipwreck to be salvaged is located under the water surface are substantial. These problems become particularly manifest when the weather conditions give cause to a rough sea but also, when it is not so much the weather conditions but a limited amount of space, the existing salvage constructions often fail to meet the preconditions de- manded by the circumstances .

It is the object of the invention to provide a method and a salvage construction that can be used in a variety of weather conditions and that is, in addition, suitable to be used for salvaging large ships, even if the available space surround- ing the shipwreck can only be described as very limited.

To this end, the salvage construction and the method for salvaging a shipwreck according to the invention is characterized by one or several of the appended claims .

In a first aspect of the invention, the salvage con- struction is characterized by a sawing wire extending between legs which can be positioned at both sides of the shipwreck. This makes it possible to limit the working area necessary for the salvaging operation to the area immediately surrounding the shipwreck . This is facilitated in particular when the salvage construction is designed such that the legs that can be positioned at both sides of the shipwreck are embodied with first frames and second frames that cooperate with each other to move the sawing wire in the horizontal and vertical direction within the boundaries of the portal.

Preferably, the salvage construction according to the invention is effectively equipped such that it comprises hoisting means for lifting the shipwreck or sections thereof.

A favourable embodiment of the salvage construction ac- cording to the invention is further characterized in that the legs of the portal are provided with adjustable feet.

In accordance with the invention, salvaging a shipwreck employing the just explained salvage construction preferably takes place such that the portal is placed over the shipwreck and that hoisting means of the portal are coupled with a shipwreck section, that subsequently a sawing wire is activated for sawing the shipwreck section off the shipwreck that is coupled with the hoisting means, and that subsequently the shipwreck section is hoisted and placed on a floating body, after which the floating body with the sawn off shipwreck section can be removed.

For the floating body it is preferred to use a pontoon. Prior to removing the floating body with the shipwreck section placed thereon, it is further desirable to increase the floating power of the floating body such that it lifts the shipwreck section and the portal, with the legs of the portal lifting from the ground, after which the floating body with the portal is moved to a following position for placing the portal over the remaining section of the shipwreck, where the floating power of the floating body is decreased and the legs of the portal come to rest on the ground.

Hereinafter the invention will be further elucidated by way of an exemplary embodiment, in which the salvage construction according to the invention is shown, as well as a few steps of the salvaging operation the shipwreck, one thing and another with reference to the drawing. The drawing shows in:

- Fig. 1 and Fig. 2, a side view and frontal view of the salvage construction according to the invention in a first stage of salvaging a shipwreck;

- Fig. 3, a schematic representation of a saw cut made in the ship to be salvaged;

- Fig. 4, a detail showing frame portions with which the sawing wire is moved horizontally and vertically, respectively;

- Fig. 5 and Fig. 6, respectively, an overview figure of the sawing operation represented in detail in Fig. 3 and in

Fig. 6, a portion of the ship being hoisted after completion of the sawing operation;

- Fig. 7, the sawn-off shipwreck section being hoisted;

- Fig. 8, the shipwreck section being placed on a pon- toon;

- Figs. 9-12, the portal being lifted and moved with the aid of the pontoon, and

- Figs. 13-16, the portal being lifted and moved with the aid of two laterally positioned pontoons. Similar parts in the figures carry the same reference numerals .

Fig. 1 shows a salvage construction 1 for salvaging a shipwreck 5 which, as can be clearly seen in Fig. 2, takes the form of a portal, provided with legs 12, 13 for positioning at both sides of the shipwreck 5.

In accordance with the invention, a sawing wire 7 is provided between the above referred to legs 12, 13 that are placeable at both sides of the shipwreck 5. To this end, the legs 12, 13 to be placed at both sides of the shipwreck 5 are embodied with (see in particular Fig. 4) first frames 2 and second frames 3 co-operating with each other to move the sawing wire 7 in the vertical and horizontal direction within the boundaries of the portal. This movement is clearly represented by means of the horizontal and vertical dotted lines 14, 15 shown in the Figures 1 and 3.

Before activating the sawing wire 1, it is important for the shipwreck section 6 that needs sawing off to be coupled to hoisting means 4 {for example winches) provided on the portal, and serving for lifting the shipwreck and, more particu- larly, the shipwreck section 6.

It should further be noted that the legs 12, 13 of the portal are provided with adjustable feet, so as to allow for un- evennesses on the ground on which the portal is positioned.

These adjustable feet are indicated with reference numeral 16 in Fig . 2.

The hoisting means 4 are coupled to the shipwreck section 6, for example, with the aid of hooks 10 to be provided on the shipwreck section 6.

It has just been mentioned that prior to making the saw cut, the shipwreck section 6 to be removed from the shipwreck 5 is coupled to the hoisting means 4 of the salvage construction 1. This is again shown in Fig. 5. After completing the saw cut, the hoisting means 4 can be activated and with their aid the shipwreck section 6 can be removed from the shipwreck 5, as shown in Fig. 6.

Fig. 7 further shows the operation of hoisting the sawn off shipwreck section 6, while Fig. 8 shows this sawn off ship- wreck section 6 being placed onto a floating body in the form of a pontoon 11.

In the Figs. 9-12 the portal 1 is shown to be moved by means of a pontoon 11, which is placed in a central position between the legs 12, 13 of the portal 1, and in the Figs. 13-16 by means of two pontoons 11 placed in a lateral position with respect to the portal 1.

In the situation shown in Figs. 9, 10 and Figs. 13, 14, respectively, the floating power of the pontoon or pontoons is first increased such as to enable this floating body 11 to lift the salvage construction 1 from the ground, as shown in Fig. 11 and Fig. 15, respectively. By means of the floating body 11, the salvage construction 1 can subsequently be moved from this lifted position to a following position as indicated with the arrows A in Fig. 12 and Fig. 16. After the floating body 11 has arrived at the newly to be taken up position, its floating power may be decreased again, so that the salvage construction 1, or rather its legs 12, 13, come to rest on the ground. After that, the sawing off and removal of a following section of the shipwreck 5 may take place in the manner described above with refer- ence to Figs. 1-8.