5.2 DC Working Distances, Safe Stepping & Bridging Risks

5.2 DC Working Distances, Safe Stepping & Bridging Risks

Conductor rails sit at ground level, right where you walk and work. Rule Book Handbook 17, DC electrified lines (GERT8000-HB17, Issue 6 in force from 6 June 2026), sets out the personal safety rules, and section 1.4 of the PTS handbook (RT3170) summarises them for PTS holders.

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What You Must Treat as Live

HB17 says conductor rail equipment (CRE: the conductor rails and anything connected to them), shoe gear and under-floor electrical equipment on trains are dangerous, and it may be fatal to touch or go near them. Treat them as live at all times unless one of the following applies:

• a planned isolation has been taken and a conductor rail permit has been issued to the COSS;
• a temporary isolation has been taken as shown in the infrastructure manager's instructions;
• a local isolation has been taken as shown in local isolation instructions;
• in an emergency, the ECO has confirmed that the CRE is safe to approach but not to touch, or the ECO has stated it is switched off and local staff have told you it is safe to approach but not to touch.

If you have live line testing equipment or a short-circuiting bar, use them before touching CRE.

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Things You Must Never Do

HB17 section 3.1 says you must not:

• touch or step on CRE, shoe gear, associated exposed live train-mounted equipment or guard boarding;
• allow clothing, tools, equipment or anything you are carrying to touch them, unless the item is intended for that purpose;
• step between the conductor rail and the adjacent running rail;
• touch broken or displaced CRE;
• touch the collector shoes on any train, whether or not they are touching the conductor rail;
• step into flood water that may be in contact with the CRE or train equipment;
• direct a jet of water or any other liquid onto them.

Traction return current in the running rails is not normally dangerous, but you must not touch broken running rails or bridge the gap between them. Treat cables running alongside and crossing under the lines as live, and do not interfere with them or their covers.

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The 1.5-Metre (5-Foot) Rule

Two further rules sit inside that exception:

• Where your company instructions allow work with the CRE live and you, or anything you are holding, will be nearer than 300 mm (1 foot), you must, if possible, place a conductor rail shield over the conductor rail before you start.
• If you must manually operate or secure points where the conductor rail is live and not gapped or protected by guard boarding next to the motor or blade, place a conductor rail shield over the conductor rail first.

     you and anything you hold                      live conductor rail
          o                                              +-----+
         /|\   <---------------- 1.5 m (5 ft) ---------->| CR  |
         / \                                             +-----+
                closer only under an approved method statement and
                electrical risk assessment; within 300 mm fit a
                conductor rail shield if possible

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Moving Materials and Attending to Vehicles

Moving materials or equipment (HB17 section 4.2): apply the precautions in the method statement or company instructions and take extreme care when holding and moving long items, using brake sticks and shunting poles, and selecting and using the correct type of electrically insulated tools and equipment. Avoid carrying materials over CRE, and never drag objects across or drop them on live CRE.

Attending to vehicles (HB17 section 4.3): if possible, work on the side furthest from live CRE when operating handbrakes, coupling or uncoupling, passing beneath buffers, going underneath or examining vehicles. If that is not possible (other than for handbrakes), first place a conductor rail shield over the conductor rail. You may examine a vehicle without the electricity being switched off as long as you do not touch the conductor rail, overhead trolley wires or equipment connected to them; after severe arcing, confirm the CRE is switched off first.

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Stepping and Crossing

The PTS handbook tells you to cross the line without stepping on the rails or sleepers, walking ballast to ballast. On a line with a conductor rail that means:

Where you have to cross, do so only where and when the COSS has arranged, step clear over both the conductor rail and the adjacent running rail together, and land on firm ballast.

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Bridging and Arcing

Bridging happens when something conductive connects the live conductor rail to the running rail or another earthed object: a metal bar, a measuring tape, a chain, a wet rope, or a person. The result is a short circuit and an arc flash: an intense flash of heat and light, molten metal and a pressure wave that can cause severe burns, eye injuries and electrocution.

• Keep metal tools, tapes, chains and long items away from the conductor rail, and never let anything rest across it.
• The PTS handbook warns that liquids become live if they touch a conductor rail; keep clear of flood water.
• Where work near live CRE is authorised, use the insulated tools and equipment the method statement specifies. Insulated hand tools for live working are made to EN 60900, which covers tools for use up to 1,000 V AC and 1,500 V DC; inspect the insulation before use and do not use a tool with damaged insulation.

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Track Circuit Operating Clips and Detonators on Conductor Rail Lines

HB17 section 4.1 and the PTS handbook add rules for emergency protection equipment:

• Apply a track circuit operating clip (or T-COD) to the running rail furthest from the conductor rail first, then to the rail nearest to it. Remove it in the reverse order: nearest rail first.
• Where there is a fourth rail, you are not able to use a track circuit operating clip.
• Place detonators on the running rail furthest from the conductor rail.
• If the emergency services need to go on or near the line and you are the person in charge at the site, tell the officer in charge of each emergency service about the conductor rail and which parts have been switched off.