On Saturday 11 April 2009 08:31:55 Joe Greco wrote:
Speaking of that, a manhole cover is typically protecting some hole, accessway, or vault that's made out of concrete.
An oxyacetylene torch or a plasma cutter will slice through regular steel manhole covers in minutes. You can cut the concrete, too, for that matter, with oxyacetylene, as long as you wear certain protective gear. We have a few vault covers here that are concrete covering the largest vaults we have. You need more than a manhole hook to get one of those covers up. The locking covers I have seen here put the lock(s) on the inside cover cam jackscrew (holes through the jackscrew close to the inside cover seal rod nut), rather than on the outside cover, thus keeping the padlocks out of the weather. One way of making a site more resistant to 'inside job' issues is with SCIF- like controls (see http://en.wikipedia.org/wiki/Sensitive_Compartmented_Information_Facility ) and using combination locks such as the Sargent and Greenleaf 8077AD for control, and the S&G 833 superpadlock for security (see http://www.sargentandgreenleaf.com/PL-833.php ). The tech would have the 833's key, and the area supervisor the combination. The 8077AD's combination is very easily changed in the field, and could be changed frequently. The key to this method's success is that the keyholder to the 833 cannot have the combination, and the holder of the combination cannot have an 833 key. Requires a certain atmosphere of distrust, unfortunately. And slows repairs way down, especially if the 833's key is lost....