shoring and its techniques
Download as DOCX, PDF4 likes7,569 views
Shoring is used to support damaged structures like bulkheads and decks against abnormal pressure from leaks or flooding. There are three main types of shoring: vertical, horizontal, and V or K-shaped. Common shoring equipment includes wooden spars, wedges, pads, and adjustable steel spars. Splinter boxes are used to patch holes with ragged edges, while cement boxes can stop small leaks in difficult areas. Improvised materials like boards can also act as emergency leak stoppers. Proper shoring techniques involve using proud, breast, and pad pieces cut to length with gunter battens to support structures without slipping or damage.
shoring and its techniques
- 1. SHORING AND ITS TECHNIQUES: SHORING: Many of the leak-stopping devices described above depend on shoring for their efficiency. Shores also have other very important functions in a damaged ship. Support of straining bulkheads, decks, doors and hatches against abnormal pressure. Support for damaged and weakened structure and fittings. TYPES OF SHORING: Three types of shoring are: Vertical. Horizontal. V or K type. SHORING EQUIPMENTS: 1. wooden shoring spar 2. steel adjustable shoring spare 3. wooden wedges 4. wooden plugs 5. wooden pads 6. splinter box 7. strong back 8. gunter batten 9. saw and hammer 10. wooden or plastic hammer
- 2. SPLINTER BOX: These are used for patching holes with ragged edges. They are available in three sizes, 300mm x 175mm, 450mm x 200mm and 600mm x 225mm. One face is open and has rubber seal around its edge, opposite face being closed and with a 15mm hole in its center which is blanked of with a bolt and butter fly nut and washer. The box can be held in place by a shore. CEMENT BOX: Small hole near boundaries in difficult corners can be dealt by using small cement boxes. The material used as a leak stopper is raped hardening cement (FONDU), which is semi permanent repair material. Unlikely ordinary commercial (Portland) cement, which take some time to hard. It sets about in 6 hours and harden in about 24 hours. IMPROVISED LEAK STOPPERS: The shape and extent of hole in the hull may prevent splinter boxes patch packs but adequate leak stopper can be improvised using material ready to hand. Table tops are similar flat boards may be considered as emergency stopper plate. Sealing between the stopper and the hull can be achieved using bedding, short mate or soft furnishing. SQUARE SHORING: For bulkheads, ship’s side plating, watertight doors and for leak stopping devices on them A proud shore is a shore cut longer than the height between decks (add 20mm), the head placed against a girder or a welded-on lug, and the heel jammed on the deck below. A breast shore is then carefully cut to jam down as nearly horizontal as possible between the proud shore and the structure to be supported. With accurate cutting of the shores, wedges are unnecessary. BASIC INSTRUCTIONS FOR SHORING: Bulkheads if the strain is due to water pressure on the other side, at one-third of the height and at the centre of width of the bulkhead. Full advantage must be taken of beams, pillars and heavy, fixed fittings to anchor the shores.
- 3. DECKS: Pad pieces will always be needed at both ends of a vertical store. For vertical shores to abut under a beam, pad pieces or shoring material must be laid across under the beams. If a deck is bulging because of pressure underneath,the foot of the shore should be over the distortion if possible. If a number of vertical shores are to be fitted in line,a length of 100mm × 100mm timber should be used as a continuous pad piece. TIMBER SHORING SPARS: The main and best material for shores is softwood, ie pine or fir. It can be easily handled, cut, fastened and, compared to hardwood, has a higher strength/weight factor. Mild steel dogs (staples), and nails are used for securing shores, pad pieces and battens together. When stowed onboard, the shores, planks and battens should be cut to the greatest length that can be moved through the ship. ADJUSTABLE STEEL SHORES: he adjustable steel shore consists of two telescopic, tubular steel sections, supplied in two sizes, o 1.75m extending to 3.1m and o 1m extending to 1.68m. It is fitted with head and base plates and provided with a screw jack, with drop handle, for fine adjustments. They should only be used as vertical or breast shores, never as proud shores. A shore must be carried vertically, with the threaded portion uppermost. The pin must be fully inserted just below the rotating collar. To prevent the pin from moving it must be held in place They are always to be used in conjunction with wooden pad pieces to: Reduce the danger of slipping. Spread loading on the structure. Prevent damage to GRP splinter boxes. GUNTER BATTENS: Gunter battens are used for measuring the length to which shores are to be cut. It is a pair of two wooden batten with no scale, with one screw. It is used in flooded area and in darkness
- 4. Gunter battens are used for measuring the length to which shores are to be cut. Two sizes should be made, one 1500mm long and the other 750mm. THE EMMS DAMAGE REPAIR CLAMP: This item is designed to be used in pairs and can replace proud shoring systems when supporting patching or other leak stopping devices. Its use alleviates the problems of access and stowage associated with providing long lengths of shoring timber in such spaces, and allows shoring to be cut to shorter lengths as required. Three types of Emms clamp are provided: Standard Small. Standard Large. Universal.