MEWP / cherry-picker operators, facade, cladding and glazing installers: the wind call, at your height

Your main decision is whether to go up in the MEWP and keep working, based on the wind at platform height. This call needs to be made for each job and re-checked every hour. The machine's data plate and the manufacturer's guidance, often supported by IPAF guidelines, specify the wind limits for operational use.

Working with facades, cladding, or glazing means you are often handling large panels that act like sails in the wind. This increases the risk of losing control, damaging materials, or endangering personnel. The wind conditions at ground level can be very different from those at 20 metres, where you might be working.

If you make the wrong call, it can lead to significant downtime. Your booked access plant and glazing crew could be left idle, and valuable panels might be held on site, leading to project delays and additional costs. Having clear, reliable wind data for your working height helps you make informed decisions, reducing these risks and keeping your project on schedule.

The Wind Agent instrument shows you the wind at 10, 80, 120, and 180 metres. For MEWP operations, you can set your working height to 20 metres, and the instrument interpolates the wind speed for that specific height. This is crucial because wind conditions at ground level often do not reflect what you experience at platform height.

Your concern is the gust at platform height, not the mean wind speed. Gusts are sudden, short increases in wind speed that can exert significant force on large surfaces like glass panels or cladding. The instrument displays gusts alongside the mean wind speed, allowing you to focus on the critical metric for your work.

Your limit for operating a MEWP outdoors is typically 12.5 m/s (28 mph, Beaufort 6) for gusts at platform height, as set by the machine's manufacturer and outlined in standards like BS EN 280. For indoor-only machines, this limit is 0 m/s. You input your specific limit into the instrument, ensuring all forecasts and alerts are tailored to your operational requirements.

The instrument provides the P(above your limit) by the hour, which is the fraction of ensemble members that predict wind speeds exceeding your set limit at your working height. This helps you understand the likelihood of encountering conditions that prevent you from working.

When the odds are, for example, 20 per cent, it suggests that a small number of possible weather scenarios show wind speeds above your limit. You might proceed with caution, keeping a close eye on conditions and ready to stop if needed. If the odds are around 50 per cent, it indicates a significant chance of exceeding your limit, prompting you to consider delaying work or planning for interruptions.

If the odds reach 80 per cent or higher, it means most of the ensemble models are predicting winds above your operational limit. In such a scenario, it is often prudent to reschedule the work or delay going up until conditions are more favourable. The Agreement Spine feature shows you where the different weather models agree and disagree, giving you insight into the forecast's certainty. When models agree, the forecast is generally more reliable.

This is an example day. At 06:00, you check the forecast and see that the wind at 20 metres is expected to be 8 m/s, with gusts of 10 m/s, well below your 12.5 m/s limit. The P(above your limit) is 10 per cent, and the Agreement Spine shows good model consensus, so you plan to proceed with the glazing work.

By 09:00, as the crew arrives, the forecast for 11:00 shows gusts rising to 12 m/s, with the P(above your limit) now at 30 per cent. You decide to start, but with a plan to monitor conditions closely.

At 11:00, the instrument updates. Gusts are now forecast to hit 14 m/s around 13:00, with the P(above your limit) at 60 per cent. You decide to complete the current panel installation but prepare to lower the MEWP and pause work at lunchtime.

By 13:00, the wind has indeed picked up. The forecast for 15:00 shows gusts dropping to 11 m/s, and the P(above your limit) falls to 20 per cent. You then plan to resume work after 15:00, allowing the wind to ease.

Your operational limit for wind speed is a critical input for the instrument. This limit is not set by The Wind Agent; it comes directly from your own documentation, such as the machine's data plate, manufacturer's operating manual, or your company's risk assessment.

For most outdoor MEWPs, a commonly cited limit for gusts at platform height is 12.5 m/s (28 mph, Beaufort 6), as specified in standards like BS EN 280. You type this value into the instrument, ensuring that all forecasts and alerts are tailored to your specific operational constraints.

The instrument is preset for a MEWP operator at a working height of 20 metres, with a gust limit of 28 mph (approximately 12.5 m/s). This setup ensures that the wind data you receive is relevant to the conditions you will encounter at the height of your work. It allows you to make informed decisions based on your specific equipment and operational guidelines.

The instrument maintains a dated record page of what was forecast, what was observed, the limit you used, and the call you made regarding work. This record is a factual account of the wind conditions and your response to them. This detailed log provides an objective reference point for your operational decisions.

This record is particularly useful for demonstrating due diligence. If a main contractor or client queries delays due to wind, you can provide a clear, objective record that you stopped work because conditions exceeded your operational limits. This helps to avoid disputes and confirms that you adhered to operational guidelines. It also offers a transparent account of your decision-making process, which can be important for project reviews or audits.

For your own operations, reviewing past records can help you understand how often wind affects your work and how accurate your decisions have been. This historical data can support future planning and resource allocation, helping you to anticipate potential wind-related delays and manage project timelines more effectively. It allows for a continuous review of your operational practices against actual weather conditions.

Ireland's geographical position means it is often exposed to Atlantic weather systems, which can bring strong winds, particularly during the storm season from October to March. This seasonality means that MEWP operators, facade, cladding, and glazing installers frequently face challenging wind conditions, making accurate wind data essential for daily operations.

Operating MEWPs in these conditions requires a clear understanding of wind speeds at height, not just at ground level. The national forecaster, Met Éireann, provides general weather information, but your work requires specific data at your working height to inform your hourly decisions. This precision helps you to manage tasks such as lifting large panels, which are highly susceptible to wind forces.

Guidance from bodies like IPAF is widely used in Ireland, emphasising the importance of understanding wind ratings for MEWPs. The Wind Agent instrument provides the precise, height-specific wind information you need to operate efficiently within these guidelines, helping you manage the risks associated with Ireland's often windy climate. It supports adherence to best practices in a demanding environment.