Page 22 - Loss of the VOC Retourschip Batavia, Western Australia, 1629

Figure 10. A diver inspecting the exposed hull timbers below cannon No. 5.
A large-capacity, road-drill compressor was used to operateair-liftsandair-poweredtools.Twodifferentunits were used during the various seasons; a small 2500 IImin unit and a larger one, 4000 I/min. The small unit was a V olkswagen engine, in which the two left-hand cylinders of the horizontally opposed engine had been converted to a compressor. This provided a very compact unit occupy- ingasmalldeckspace.ThelargerunitwasaRota-Vane compressor driven by a diesel engine. This occupied a large area on the deck and proved to be unsuitable for free- flowrunning,sinceitwasdifficulttogettheadequateback pressure that rotary compressors require. The air-supply hoses for these units were mounted on the cabin roof.
Two small 5 m aluminium dinghies were used for running around the islands and working on the inside reef. For safety, the main 18 kw (25 HP) outboard engines were supplemented with stand-by 7 kw (9.5 HP) outboards. Emergency equipment was housed in a water-tight con- tainer, providing the basic tools to repair the engines, a survival kit to last several days, and all standard boat emergency requirements (flares, fire extinguisher, torch,
During diving operations on the wreck site, the work- boatwasmadefasttoaspeciallyconstructedmooring.Two 200kgstockedanchorswereattachedinaVconfiguration to 100 m of heavy-link chain; 250 m of high-tensile chain was run from the mid-point of the heavy chain back to the wreck site. A 50 kg anchor was laid slightly to one side of the middle of the wreck site. Two chain risers, connected to the high-tensile chain at 50 m and 75 m from the wreck site, wereattachedtodanbuoyssothattheendscouldbepicked up from the boat. Thus, on fine days, the workboat was moored on the 50 m riser and, should the vessel need to lift heavy objects, it could be let back over the site on an additional hawser. In the I1Ite cases where the wind was not blowing in the same direction as the prevailing swell, a stem rope attached to the wreck site anchor was used to draw the vessel into a bows-on configuration to the swell. In heavy swell conditions, the vessel was moored on the outer mooring. In all cases, the greatest danger was always related to the workboat, necessitating that, at all times, the vessel be securely chained to the mooring. Diving was invariably terminated not because of any danger to the divers, but rather the danger posed to the workboat due to
first-aid kit etc.).
increasing swell.
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