Forums Forums Traffic Signals Slot cutting – encapsulate requirements Reply To: Slot cutting – encapsulate requirements


Hi Alan thanks for sharing your experience. A conversation with the slot cutters corresponds with what you are saying. Does concern me a bit the temperature of the bitumen being poured and the cable only rated to an operating temperature limit of 85 degrees C though presumably a short duration of a higher temperature won’t damage it, though it doesn’t spec any limits other than the operating temperature in TR2029. Not sure about BS6500/6195, not checked.  Given the widespread use of bitumen direct onto the cable and the generally low failure rate then investigating this as a reason for premature loop failure probably not worth pursuing. Begs the question though, where is bitumen direct onto the cable specified as a standard installation means? Siemens have a pretty good guide on loops and the methods spec’d there are dry sand then hot pour bitumen or epoxy resin then hot pour. Many would refer to HCD G series which does specifically differentiate the encapsulant from the hot pour bitumen . I think its probably the case on a number of jobs I’ve had involvement on that the signals contractor isn’t fully communicating the requirements of the 12/5 to the slot cutters, probably assumptions are being made about what the original requirement was.