MineCam

The MineCam is a remote exploration camera built by I.A.Recordings. It is used for mine shaft exploration and other similar environments. It was originally conceptualized in 1988, and since went under several design revisions. The name MineCam, is a pun on MiniCam, an early hand-held broadcast camera built by CBS Laboratories.

Peter Eggleston of I.A.Recordings first had the idea for what became "MineCam" in 1988. He had been visiting some metal mines in Wales with the Shropshire Caving and Mining Club and spent several hours setting up a single rope technique rig to descend a remote shaft, only to find that there were no ways off at the bottom. This was the motivation to build a miniature camera which would allow enthusiasts to explore hard to reach, unsafe, or impossible to reach areas.

The remote exploration of mines prior to 1988 had been done commercially for several years by pipeline camera firms using equipment that needed to be housed in a vehicle and powered by a generator. Many old mine shafts are remote from roads though, so Peter's final goal was a small lightweight battery-powered kit which could be carried on foot. The first two versions of MineCam did not achieve this, but tested various approaches with the video technology available at the time.

MineCam 1 used a monochrome vidicon camera in a waterproof housing made out of a 10 cm plastic sewer pipe and fittings, with an acrylic window. This was successfully tested in the deep end of a swimming pool. The camera was insensitive - it needed a 150 W lamp, which required a 240 V supply, but so did the camera. The cable was 100 m of video co-axial and power, taped together at 2 m intervals and numbered to give a crude depth measurement. The camera and lamp were heavy, so an old 6 mm static climbing rope was used to support it. The monitor was a 10 cm portable TV.

MineCam 1 worked, but the monochrome image was sometimes difficult to interpret. It was time to try colour, and this was not yet available from the commercial shaft inspection firms.

MineCam 2 used parts from a disused Sony 'Handycam.' The colour CCD chip was removed and put in a round tobacco tin connected by a short cable to the rest of the electronics in a small Eddystone die-cast box. The 'Eddy box' contained extra hardware to convert the Y/C (700 kHz) direct colour-under output to composite PAL, and provide various unusual power supply voltages. Because of the colour stripe filter and the early technology, this CCD was only as sensitive as the monochrome vidicon.

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