NR NR/SIN/090 ISSUE 1 PDF

This Special Instruction Notice applies to rail-foot mounted brackets used to secure Adjustable Stretcher Bars on shallow-depth switches. The approved fasteners for fixing these brackets were the ‘Kep' nut and MGLP however in some cases unapproved nut-and-bolt type fasteners have also been used. This standard mandates the replacement of ‘Kep' nuts and unapproved fasteners. The new replacement fastener system comprises an M20 bolt, 3° taper-washer, Vibro-lock washer and Philidas nut. The use of MGLPs is to be phased out although they can still be used to address the requirements of this SIN but only until stocks of MGLPs are exhausted.

The requirements of this SIN apply to all UIC54B S&C. There is also small number of other types S&C details of which are given below:

• 113A S&C fitted with Type 2 brackets;
• RT60 S&C manufactured by VAE fitted with Type 2 brackets;
• UIC54B switch-diamonds fitted with Type 4 brackets;

This standard does not apply to:

• 113A full-depth S&C where fixed stretcher bars are used;
• front Adjustable Stretcher Bar assemblies fitted on UIC54B layouts where Type 1, web-mounted brackets are used.

Purpose

This Special Inspection Notice mandates the replacement of the all temporary ‘Kep' nut fasteners and other non-approved fasteners with a new type fastener or an MGLP. Full details of the new fastener, including how it is to be fitted are given below.