Masts and towers
Sway at the head of a mast through every season, set against the loading it carries. A structure that starts moving more after new equipment is fitted shows on the trend.
Sway and movement monitoring tag
The ZARC sway and movement tag samples how much a structure moves, over time, and reports the average, the maximum and the minimum for each period. It builds a long-term record of how a mast, tower, crane or temporary structure behaves in wind and under load, and raises an alert when movement passes a limit you set. It is fixed to the structure, runs on its own battery and needs no wiring.
01
What it reports
The tag samples movement continuously and summarises it for each reporting interval as an average, a maximum and a minimum. The interval is set for the site, down to every minute.
It is long-term data by design. One reading of a mast in a gale means little. Months of readings show what normal movement looks like for that structure, how it responds to wind, and whether it is moving more this year than last.
The record has a second use. When a structure, an antenna or a fitting fails, the question is what it went through. A dated history of maximum movement supports an insurance claim, a warranty claim, or the defence against one.
Alerts can be set on a level, on a trend, or on time spent above a limit, so a single gust does not page anyone and a structure moving more every week does.
The tag supports the people responsible for a structure. It does not replace a structural inspection or an engineer's assessment, and it is not a safety system for lifting operations.
02
Applications
Structures move. The question is how much, how often, and whether that is changing. The uses below are the common ones.
Insurance and warranty claims
A dated record of the maximum movement a structure or its equipment experienced, before and during a storm or a failure.
Cranes and lifting equipment
A long-term picture of how a crane moves in service and out of service. It is a record, not a lifting safety system.
Temporary works
Scaffolds, hoardings, props and facade retention, where movement is expected to stay small and an increase means something has changed.
Lighting columns, signs and gantries
Columns and sign structures that work loose or fatigue over years, flagged by movement before they are found by inspection.
Walls and structures beside excavation
Slow movement of a retaining wall, facade or neighbouring building while work goes on next to it.
Wind and solar structures
Frames, masts and mountings exposed to wind every day of their lives.
After a storm
Which structures on an estate moved most, so inspections go to those first.
Antenna and dish alignment
Movement at the mounting that explains a link dropping in high wind.
Heritage structures
Towers, spires and chimneys, watched over years without fixing a cable to them.
03
Where it can go
The tag is fixed to the part of the structure whose movement matters. Typical positions:
At the head of a mast or tower
Where sway is greatest.
On a crane jib or mast
Clamped clear of moving parts.
On scaffold and props
At the points an engineer names.
On columns and gantries
Near the top, inside or outside the column.
On walls and facades
Fixed flat to the surface being watched.
At antenna mountings
On the bracket, beside the antenna or dish.
04
In the dashboard
Every tag shows its current movement and a trend from the last hour to the last year. The dashboard holds the average, maximum and minimum for every interval, picks out the largest movements and when they happened, and sets structures side by side so the one that moves most is obvious. Records export with dates and times for engineers, insurers and warranty claims.
Limits are set per tag: level, trend and duration. When one is crossed the alert is raised in real time and goes by email or SMS, and through an app where required, to the people you name, with escalation to further contacts.
- Current movement for every structure
- Average, maximum and minimum for every interval
- Largest movements and when they happened
- Trend graphs from one hour to one year
- This season against last season
- Structures compared side by side
- Limits on level, trend and duration
- Every alert logged with the reading that raised it
- Records exported for engineers and insurers
- A tag that misses its reporting interval is flagged
05
Industries
Sway and movement tags are fitted wherever a structure stands in the wind or carries a changing load, including:
Telecoms infrastructure
Masts, towers and antenna mountings.
Construction and temporary works
Cranes, scaffolds, props and retained facades.
Energy and utilities
Masts, frames and exposed plant.
Transport
Lighting columns, signs and gantries.
Local government and public sector
Street furniture and public structures.
Critical national infrastructure
Structures on unmanned sites.
06
Technical specification
| Parameter | Specification |
|---|---|
| Measurement | Movement and sway of a structure, sampled over time |
| Sensing | Motion sensing inside the tag; sensitivity set to the structure |
| Values reported | Average, maximum and minimum for each reporting interval |
| Range and accuracy | Specified to the requirement |
| Reporting interval | Configurable, down to every minute |
| Long-term record | Every interval kept, for comparison across seasons and years |
| Limit alerts | Movement above a limit you set |
| Trend alerts | Movement increasing over weeks or months, at a rate you set |
| Duration alerts | Time above a limit, so a single gust does not alarm |
| Alert delivery | Dashboard, email or SMS; app where required |
| Recipients | Named people and groups, with escalation to further contacts |
| Gateway power loss | Raises its own platform alert |
| Missed reports | A tag that misses its reporting interval is flagged in the dashboard |
| Dashboard | Current movement, trends, average/max/min, largest events, structures compared; configured to your requirement |
| Records | Every reading time-stamped and exportable for engineers, insurers and warranty claims |
| Data | Full history; UK-hosted or on servers on your own site |
| Power | Internal battery, up to five years as standard; longer with additional cells |
| Radio | 433 MHz, one-way (transmit only) |
| Radio range | Site-dependent; confirmed by site survey |
| Environment | Indoor or outdoor, enclosure specified to the location |
| Mounting | Clamped or bolted to the structure; no cable |
| Enclosure | Weatherproof, specified to the exposure |
| Not for | Structural inspection, an engineer's assessment or lifting safety systems |
| Charges | No per-alert, per-user or licence charges |
| Manufacture | Made to order in the UK |
| Certification | CE marked |
07
From requirement to live alerts
Requirement
Tell us the structure, what movement would concern you, and whether the record is for engineering, insurance or both.
Configuration
Each tag is built to order with its sensitivity, reporting interval and limits set for the structure.
Fitting
The tag is clamped or bolted in place at the point agreed. No cable is run up the structure.
Commissioning
The first weeks set the baseline of normal movement, and limits are confirmed against it with the engineer responsible.
Ready to get started? Every deployment begins with a site survey.
Book a site survey08
How it reports
Each interval's readings go over 433 MHz radio to a ZARC gateway at the foot of the structure or nearby, and on to the dashboard. The tag has a transmitter and no receiver. With no cable to run and a battery that lasts years, it stays at the head of a mast without a climb to service it.
Related tags
Crystal motion
An item lifted, tilted or moved, reported as an event.
Air pressure
The falling barometer ahead of a storm.
Power failure
Loss of supply at the same site.
Temperature
Conditions in the cabinet at the foot of the structure.
Questions we answer most.
What does the sway and movement tag measure?
How much a structure moves over time, reported as an average, a maximum and a minimum for each period.
Why sample over time instead of taking one reading?
One reading means little. Months of readings show what is normal for the structure and whether it is changing.
Can the data support an insurance or warranty claim?
Yes. Every reading is time-stamped and exportable, including the maximum movement before and during an event.
Can it alert when a structure moves too much?
Yes. Alerts can be set on a level, on a rising trend or on time spent above a limit.
What structures is it used on?
Masts, towers, cranes, scaffolds, lighting columns, gantries, walls and antenna mountings.
Does it replace a structural inspection?
No. It supports the people responsible for a structure and does not replace an inspection or an engineer's assessment.
Is it a crane safety system?
No. It is a long-term record of movement, not a safety system for lifting operations.
Does it need a cable up the structure?
No. It runs on an internal battery and reports by radio to a ZARC gateway.
How long does the battery last?
Up to five years as standard, and longer where additional cells are fitted.
How is it different from the crystal motion tag?
The crystal motion tag reports an event when an item is lifted or moved. This tag samples continuous movement and reports how much.
Looking for something else?
We work with any sensor for any application.
Most sensing needs are met by a tag we already build, configured for your equipment. If yours needs a sensor or interface we don't list, we have the engineering to build it. Tell us what you need to measure, and we will tell you how we would do it.
Discuss your requirementDiscuss a monitoring
or alerting solution
Tell us what is happening on site, what you need to see, and the event you need to hear about. We will come back with the system that answers it.
Direct contact
Location
Venator House, Unit 9, 15-17 St Stephen's Road, Bournemouth
Dorset, BH2 6LA · VAT GB 409644484
Products contact
Contact the engineering team
Direct to the team that designs and builds the range. Tell us the equipment and the event that matters.