What is a straight (through) joint?

A joint where two lengths of the same main cable are spliced together, fibre to fibre, by colour and tube.

Why: Cable comes in drum lengths, so long sections need joining. Each joint adds loss, so they are spaced as far apart as practical.

Where: At the end of each drum length along the route, in a joint bay or suitable housing. Locations are chosen to keep the joint count low.

Where the rules are

• NR/L2/TEL/30160 cl 8.2through joints — splicing by colour and tube, incl. DI-SAC to standard
• NR/L2/TEL/31200 cl 6.1why straight joints are spaced as far apart as possible
• NR/L2/TEL/31200 cl 8.3choosing straight joint locations
• NR/L2/TEL/30160 cl 8.1general splicing rules and the splice limit per fibre

What to order

• Joint Closure FIST-GCO2-BC6-NN · Passcom · 483578-000
• Joint kit, Apex X-2S · Hybrid ES · AX-2S-B-L-6-4-0-X-NR

PADS numbers with free sign-up on each part page. More in the parts finder

On the drawing

Each joint is shown on the SLD with its ID; splicing shown on the fibre splicing drawing.

Also called: through joint, straight joint, in-line joint

Guidance in our words. Read the current issue of each standard before you design to it.