6.1 The Safe System of Work and Its Hierarchy

6.1 The Safe System of Work and Its Hierarchy

Every job on or near the line needs a safe system of work that stops people being put in danger by trains or electrification. Network Rail's standard NR/L2/OHS/019, Safety of people at work on or near the line, sets out how safe systems of work are planned, checked and authorised. Its simplified issues introduced the Safe Work Pack (SWP) and set out the roles of the Planner, the Responsible Manager and the Person in Charge (PIC), so that no single person plans, verifies and authorises a safe work pack on their own.

The PTS handbook (RT3170, section 5.3) lists the systems the COSS or person in charge may set up, and says that work will be planned to use the safest method possible. A line blockage with no train movements is the preferred option, but this is not always possible, which is why other safe systems exist.

   SAFEST   1. Safeguarded  - lines blocked, no trains on the site
     |      2. Fenced       - a fence separates the group from trains
     |      3. Separated    - a site warden keeps the group in a safe area
     |      4. Track warning systems - ATWS, SATWS, TAWS / TOWS
   LEAST    5. LOWS and lookouts - only with company director permission

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1. Safeguarded

With a safeguarded site of work, all the lines at your site are blocked to trains. This is achieved by a line blockage arranged with the signaller (Rule Book Handbook 8 covers an IWA, COSS or protection controller blocking a line) or by working inside an engineering possession controlled by the person in charge of the possession (PICOP), with worksites managed by engineering supervisors.

Inside a possession worksite, engineering trains and on-track plant may move through a safeguarded area, but only at no more than walking pace; the person in charge or COSS will brief you if this is to happen. The same arrangement can apply to fenced and site warden areas, but only within a possession worksite.

Remember that a blocked line next to an open line is not a safe area for the open line. If the adjacent line is still open, you must stay within the limits you were briefed.

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2. Fenced

A temporary fence is put up between the site and the nearest open line. There are three types: a rigid safety barrier, plastic netting or barrier tape.

If the person in charge or COSS told you at the briefing that a fence marks the safe working limit, you must stay on the safe side of the fence, not lean on or over it, and not lean objects against it. HB1 section 5.3 says you must not lean against a safety barrier or rest tools or equipment against it.

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3. Separated (Site Warden Warning)

With a site warden area, a space is provided between the site and the nearest open line:

• the space must be at least 2 metres (6 feet 6 inches);
• a site warden is appointed if there are more than two people in the group;
• site wardens are only used for static sites of work, never when walking to a site;
• if the group is just you and the person in charge or COSS, a site warden is not required, but the space must still be at least 2 metres;
• if there are more than two people and no site warden, the space must be at least 3 metres (10 feet).

The site warden wears a white armlet or badge with "SITE WARDEN" in blue letters and watches the group, not the trains. If someone strays outside the safe area towards an open line, the site warden shouts "get back!". If the person does not move back immediately, the site warden gives a series of short sharp blasts on a whistle or horn. Never distract a site warden, and if you think you might not hear their warning, tell the person in charge or COSS.

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4. Track Warning Systems

With a track warning system, you are warned when a train is coming, and the COSS or person in charge makes sure the warning gives you enough time to reach the position of safety at least 10 seconds before the train passes. The PTS handbook lists three methods in order of preference:

1. Automatic Track Warning System (ATWS): approaching trains are detected by the signalling system or by equipment attached to the running rails, and the warning is given by trackside flashing lights and sirens and/or a personal warning device. It is independent of human operation.
2. Semi-Automatic Track Warning System (SATWS): works the same way as ATWS, except that an operator cancels the warning tone and lights at the site of work.
3. Train Activated Warning System (TAWS) and Train Operated Warning System (TOWS): approaching trains are detected by the signalling system and the warning is given by trackside sirens. When the system is switched on an intermittent tone is heard; as a train gets closer the tone and frequency change.

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5. LOWS and Lookouts

Lookout Operated Warning Systems (LOWS) and unassisted lookouts using flags, horn or whistle can only be used with permission from a company director. The PTS handbook notes that lookout working is being reduced, so you may not experience it.

• Lookouts wear a white armlet or badge with "LOOKOUT" in red letters.
• Warnings are given by horn, whistle or touch (touch where there is noise or the group is wearing ear protection), and a lookout may use a cut-off device on noisy equipment.
• Rule Book Handbook 3 describes site, distant and intermediate lookouts. Distant and intermediate lookouts are not allowed in darkness, poor visibility or tunnels, and site lookouts are only allowed in those conditions where the maximum speed of all approaching trains is no more than 20 mph and there is sufficient sighting (unless LOWS is being used).

Working Out Warning Time

For any warning system, the COSS works out the warning time needed:

• Warning time = time to stop work, clear tools and reach the position of safety, plus at least 10 seconds.
• Sighting distance = warning time multiplied by the speed of the fastest approaching train.

For example, if a group needs 15 seconds to clear and reach the position of safety, the warning time is 25 seconds. At 90 mph (about 40 metres per second) a lookout would need to see trains about 1,000 metres away. If that sighting is not available, the COSS must use additional lookouts, a warning system or a higher level of protection.

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Why the Hierarchy Matters

Warning systems depend on people seeing, hearing and reacting correctly every time; protection systems remove the train or put a barrier in the way. The Rail Accident Investigation Branch investigated the accident at Margam on 3 July 2019, in which two track workers were struck and killed by a train while working on an open line, and reducing reliance on lookout warning has been a major focus of track worker safety improvement since then, as the PTS handbook's note that lookout working is being reduced reflects. As a PTS holder, you do not choose the system, but you must understand it, follow it exactly and speak up if it is not what was briefed.