Equipment Details
Product Name: Square Post Slipbase System
Description:
The test articles were cast-iron slip bases for square tube sign supports. They are designed as a slip-on collar that adapts thin-walled square tubing (nonperforated) to the triangular shaped slip-base. The adapter collar allows square tubing to be attached to triangular slip-base foundations that were originally intended for use with round pipe supports. Details for the slip-on collar are shown in Enclosure 1. The casting is fabricated from ASTM A-536 Grade 65-45-12 ductile iron. Assembly of the slip base system is illustrated in Enclosure 2. The collar of the slip base casting slides over the end of a thin-walled square tube support. A 30 gage galvanized slip plate, shown in Enclosure 3, is inserted into the end of the square tube. The casting, slip plate, and thin walled square tube support are then connected with a 13 mm galvanized steel locking pin. The triangular slip-base plated for the support and the ground stub (shown in Enclosure 4) are clamped together using three 13 mm diameter x 64 mm long ASTM A-325 hex bolts with a washer under the head and nut of each bolt. The bolts were torqued to 40 foot-pounds. A galvanized bolt keeper plate is placed between the slip planes.
NCHRP Approval: NCHRP Approved
Approval Letter Link: http://safety.fhwa.dot.gov/roadway_dept/road_hardware/breakaway/pdf/ss88.pdf
Contact(s):
Northwest Pipe Company
P.O. Box 2002
Houston, Texas 77252-2002
Contact: Mr. H. Mark Jordan
Phone: (713) 863-4300
Website: http://www.nwpipe.com/
