North American Industries Provides Crane for Special Environment in Hot Dip Galvanizing Plant
October 2007
North American Industries (NAI) was recently awarded a job to engineer a 10 ton double girder top running bridge crane for a special environment and unique duty cycle at a hot-dip galvanizing plant owned by Reinforcing Services Inc, a division of North American Galvanizing Inc. The customer hot-dip galvanizes iron and steel products by submerging them in molten zinc to provide protection against corrosion.
North American Industries is designing the crane to operate in the high heat environment with a maximum ambient temperature of 160ºF; the controls will be mounted remotely where the temperature will not exceed 104ºF. North American Industries will use a hydro-chloric resistant two part epoxy paint because improperly coated steel is susceptible to corrosion in the atmosphere at the facility. NEMA 4x electrical enclosures will be used and North American Industries plans to increase the wire size of the festoon cable and control wiring from standard sizes due to the heat and resulting ampacity decrease.
The crane system will utilize two 5 ton hoists and trolleys that can be used in tandem or independently from a radio remote control. The crane system also has to be designed with end trucks lengths not to exceed 10 feet to maximize hook coverage. The crane will be installed by North American Industries at the Port of Catoosa in Tulsa, OK.
Due to the high duty cycle, the application requires a double reeved hoist. The 30:1 drum to rope diameter ratio and a reduced amount of reversed bending is important to rope, drum, and sheave life.
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