PTS Individual Working Alone (IWA) — Questions and Answers
Question 1: What does IWA stand for in the context of railway track safety?
- Immediate Warning Alarm
- Individual Working Alone (Correct answer)
- Integrated Warning Authority
- Internal Work Assessment
Correct answer: Individual Working Alone
IWA stands for Individual Working Alone. It is a Safe System of Work that allows a single competent and authorised person to work on or near the line without requiring a separate COSS or lookout, provided specific conditions relating to line speeds, work type, and competency are met.
Question 2: Which of the following is a key condition that must be met for an IWA Safe System of Work to be used?
- The worker must be accompanied by at least one other person at all times
- The line speed must not exceed a specified maximum and the work must be of a type permitted under IWA rules (Correct answer)
- The worker must hold a COSS licence rather than just a PTS licence
- A full possession of the line must always be in place before IWA can be used
Correct answer: The line speed must not exceed a specified maximum and the work must be of a type permitted under IWA rules
IWA working is only permitted on lines up to a defined maximum speed (typically 50 mph or lower, depending on the specific rules in force) and only for tasks that fall within the scope of approved IWA work. The individual must also hold the relevant IWA competency on Sentinel.
Question 3: When working under IWA, who is responsible for providing warning of approaching trains?
- A dedicated lookout who is always required even under IWA
- The signaller, who will phone the worker before every train
- The IWA worker themselves, using their own observation and any applicable warning system (Correct answer)
- A COSS appointed by the contractor
Correct answer: The IWA worker themselves, using their own observation and any applicable warning system
Under an IWA system, the individual worker takes personal responsibility for monitoring for approaching trains and reaching a position of safety. There is no separate lookout — this is the defining difference from other safe systems. This is why IWA is restricted to lower-speed lines and limited task types.
Question 4: An IWA is only permitted on lines where the maximum permissible speed does not exceed:
- 10 mph
- 50 mph (Correct answer)
- 100 mph
- 125 mph
Correct answer: 50 mph
IWA is restricted to lines with a maximum permissible speed of 50 mph or less. At higher speeds, the time available for a lone worker to identify an approaching train and reach safety is insufficient without a dedicated lookout or COSS protection.
Question 5: How does an IWA differ from a COSS-controlled safe system of work?
- An IWA requires more workers on site than a COSS system
- Under IWA there is no separate COSS or lookout — a single competent person manages their own protection (Correct answer)
- IWA systems always require a full track possession
- IWA can only be used on electrified lines
Correct answer: Under IWA there is no separate COSS or lookout — a single competent person manages their own protection
The fundamental difference is that an IWA is a single-person system with no COSS, lookout, or warning team. The individual must be competent and Sentinel-registered for IWA. A COSS-controlled system involves a COSS responsible for a team or work group, often with lookouts and a defined warning arrangement.
Question 6: Which type of work would NOT normally be permitted under an IWA Safe System of Work?
- A single inspection walk along a low-speed siding
- A lone engineer conducting a brief visual survey on a 40 mph line
- A large team of workers laying new ballast on a 100 mph main line (Correct answer)
- An individual checking drainage equipment on a 30 mph industrial branch
Correct answer: A large team of workers laying new ballast on a 100 mph main line
IWA is restricted to individual workers and lines not exceeding 50 mph. A large team on a 100 mph main line requires a full COSS-controlled safe system of work, potentially with a possession. IWA would be entirely inappropriate for both the team size and the line speed involved.
PTS Individual Working Alone (IWA)
What does IWA stand for in the context of railway track safety?