Putting the X-series to the test

The Challenge

Wam Metals is a manufacturer and supplier of a wide range of specialized non-ferrous and ferrous components, servicing both the local South African and the international markets. The company has a long-standing and close relationship with logistics company Transnet’s Freight Rail Division, which specializes in the transportation of freight, mainly through its electrified rail network.

The contact splice conductors in the installations Wam Metals did for Transnet used to be designed to use locking plates to lock the bolts after being tightened. However numerous incidents occurred because of bad maintenance. The procedure stated that splices had to be tightened and later re-tightened, and only then could the locking plate be bent to lock the bolts.

The incidents revealed that the plates were usually intact and therefore, because of vibration in the overhead line, the bolts loosened and the contact wire pulled out of the splice.

The Solution

Wam Metals requested approval from Transnet’s Engineering Department in April 2014 to change its specifications and to start using stainless steel Nord-Lock washers instead of the locking plates. Thorough tests were carried out. The washers from Nord-Lock performed as they should, with no slip occurring, so Transnet approved the use of the new product instead of locking plates.

The Result

To date, no incidents regarding hook-ups caused by contact splices – fitted with Nord-Lock washers – have been reported. Wam Metals currently uses NLX10 for the signal bonds, NL10ss for 107mm² contact splices and NL12ss for 161mm² contact splices and the rail and mast bonds.

For Wam Metals, the use of Nord-Lock washers on the contact splices means there is no need to re-tighten at a later stage. The same goes for signal, rail and mast bonds, which translates into reduced maintenance costs and fewer hook-up incidents.

For Nord-Lock, the experience from Wam Metals is highly interesting. It is really putting the company’s X-series to the test, in a new field where the company has not previously been widely involved.