Exam prep · UK
PTS Working in a group practice questions
COSS briefings, safe systems of work, lookouts, site wardens and armbands.
Updated 8 November 2026 for the latest Rule Book
Key rules
See all 56 key rulesThe briefing must cover the nature and location of the work, the approved access point and walking route, and the site limits and how they are defined.
RT3170 Iss 11 (2024) §5.4
The briefing must cover the lines at the site, the maximum train speed and the normal direction of trains on each line.
RT3170 Iss 11 (2024) §5.4
The briefing must cover limited clearance or no-go areas and the purpose of being on or near the line.
RT3170 Iss 11 (2024) §4.4
The briefing must cover first aid arrangements, the emergency contact and the location of the nearest hospital.
RT3170 Iss 11 (2024) §5.4
The briefing must cover the best means of contacting the Signaller, the emergency services and, if necessary, the Electrical Control Operator.
RT3170 Iss 11 (2024) §5.4
The briefing must cover site hazards such as electrification equipment, buried services or poor cess conditions.
RT3170 Iss 11 (2024) §5.4
The briefing must state which lines are blocked to trains and which remain open, and the welfare facilities provided.
RT3170 Iss 11 (2024) §5.4
For Safeguarded, Fenced or Site Warden Warning systems, you are also told the safe limits of the work area and, where relevant, who the Site Warden is and their warning method.
RT3170 Iss 11 (2024) §5.4
For equipment and Lookout warning systems, you are told the position of safety, the warning method and, where relevant, who and where the site and touch Lookouts are.
RT3170 Iss 11 (2024) §5.4
On electrified lines, assume OLE or conductor rails are live and dangerous unless the COSS/person in charge tells you the equipment is isolated.
RT3170 Iss 11 (2024) §5.4
When told of an isolation, you must also be told the safe limits, any nearby equipment that is still live and where it is, and whether non-electric trains or on-track plant could still approach.
RT3170 Iss 11 (2024) §5.4
After the briefing you are questioned on the safe system of work, and you must sign the safe-work briefing form RT9909 to show you understand it.
GERT8000-HB1 Iss 9 §5.2
Sample questions
1. Your COSS is setting up a barrier tape fence next to an open line with a 75 mph maximum speed. How far from the nearest running rail must it be?
- At least 1.25 metres (4 feet)
- At least 3 metres (10 feet)
- At least 1.5 metres (5 feet)
- At least 2 metres (6 feet 6 inches)
Answer: D. At least 2 metres (6 feet 6 inches)
If the open line speed is over 40 mph, a tape or netting fence must be at least 2 metres from the nearest running rail. At that distance there is no restriction on train speed.
- At least 1.25 metres (4 feet): 1.25 metres is only allowed for tape or netting when the open line is 40 mph or less.
- At least 3 metres (10 feet): 3 metres is the site warden separated distance for a large group with no warden.
- At least 1.5 metres (5 feet): 1.5 metres is not a distance used for fences.
Source: RT3170 Iss 11 (2024) §5.3
2. What is the closest a rigid safety barrier may be placed to the nearest open line?
- 1 metre (3 feet)
- 1.25 metres (4 feet)
- 2 metres (6 feet 6 inches)
- 3 metres (10 feet)
Answer: B. 1.25 metres (4 feet)
A rigid safety barrier can be placed no less than 1.25 metres (4 feet) from the nearest open line. Its strength allows it closer than a tape fence on faster lines.
- 1 metre (3 feet): 1 metre is closer than the minimum allowed.
- 2 metres (6 feet 6 inches): 2 metres is the minimum for tape or netting on lines over 40 mph.
- 3 metres (10 feet): 3 metres is a site warden separated distance, not a barrier distance.
Source: RT3170 Iss 11 (2024) §5.3
3. A barrier tape fence may be placed 1.25 metres from the nearest running rail of an open line with a 50 mph maximum speed.
- True
- False
Answer: B. False
A tape or netting fence at 1.25 metres is only allowed if the open line speed is no more than 40 mph (65 km/h). At 50 mph it must be at least 2 metres away.
Source: RT3170 Iss 11 (2024) §5.3
4. How do you recognise the site warden's armlet?
- Blue with white lettering
- White with red lettering
- White with blue lettering
- Orange with black lettering
Answer: C. White with blue lettering
A site warden wears a white armlet or badge with 'SITE WARDEN' in blue letters, armlet on the left arm. Knowing the armlets lets you identify who is protecting you.
- Blue with white lettering: Blue with white lettering is the COSS armlet.
- White with red lettering: White with red lettering is the lookout armlet.
- Orange with black lettering: Orange with black lettering is not one of these armlets.
Source: GERT8000-HB3 Iss 4 §2; GERT8000-HB1 Iss 9 §5.2
5. While working, you hear the site warden shout 'get back' followed by short sharp horn blasts. What must you do?
- Carry on, as the warning is probably meant for someone else
- Walk to the position of safety and wait for the train to pass
- Stop and wait for the site warden to come and explain
- Check you are in the safe area and step back into it at once if not
Answer: D. Check you are in the safe area and step back into it at once if not
A site warden shouts 'get back' when someone moves beyond the safe limits, then gives short sharp blasts if they do not move back. You must check you are in the safe area and step back immediately if you have strayed.
- Carry on, as the warning is probably meant for someone else: Every warning must be checked; it could be meant for you.
- Walk to the position of safety and wait for the train to pass: A site warden warning is about the safe limits, not a train approach.
- Stop and wait for the site warden to come and explain: Waiting leaves you in the danger area.
Source: GERT8000-HB3 Iss 4 §2; GERT8000-HB1 Iss 9 §5.5