I have been operating a 1974 Hitachi Model #7335603 55st overhead container crane. The crane is primarily being used to discharge 30 to 40 ton steel slabs with braided chain slings. it is also used occasionally loading and discharging container barges.
The crane is used around 10 shifts per month, when in use it cycles around 15 to 18 slabs per hour. Both trolley rails are badly worn and mis-aligned at the boom joint area.
There is a violent bang and jolt when driving over the worn area at the boom joint. It was discovered that a triangular piece about 2 inches in length has broken off of the up river rail flange at the problem boom joint area.
There is also an easily recognizable crack in the same area just above the bottom rail flange running parallel to the ground, the crack is around 4 to 5 inches long and a pocket knife blade tip will slide into the crack. The crack does not go all of the way through.
The crack just above the bottom rail flange has probably been there for around two years, I do not know if it has been monitered. The mis-aligned and worn rails have been in that condition for at least 5 years and are getting worse.
The Port (Portland OR) will not take the Crane out of service to repair. We have a total of 9 container cranes on this pier. After reading some of the advice on this topic it seems the crane rails are unfit for further operation untill replaced. Are we in danger of operating the crane with the explained conditions.
Thanks for your time.Jack M.
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