Construction is big business, accounting for roughly seven per cent of UK GDP, or around £110bn a year. Scale comes with challenges of its own, not least safeguarding the lives of the sector’s roughly 1.27 million workers, about three per cent of whom will sustain a work-related injury each year. In addition, 43 construction workers were fatally injured in 2015/16. In such a potentially dangerous environment, it pays to be able to quickly communicate without the need to try to make yourself heard above the roar of machinery. It’s no wonder then that many companies in this sector make use of two-way radio.
John Phillips, operations director at Brentwood Communications, says it sometimes gets called in by construction firms that are using two-way radios provided by another company but aren’t getting the coverage they require. The main reason for this? “When the radio system was installed, it worked because the building was just a frame, and then as [the building] goes up and the floors and walls are put in, the coverage deteriorates and you may need more sophisticated infrastructure. It’s not the [original radio provider’s fault], it’s just that the requirements have changed because the building has changed since the original installation. It’s important for us to be in touch with the construction company regularly to make sure that as the requirements change, we install different infrastructure because requirements change quickly.
“They can have back-to-back radios while there’s no building taking place. [But], as soon as the structure starts going up, they may need repeaters and antennas to boost the coverage across the site.”
Phillips adds that construction materials can have a massive impact on coverage. Brentwood recently installed a radio system at a construction site for a hotel in London. “We surveyed it and made a recommendation, and installed [the radio system]. But a few months later when it was all built up and they had a lovely full-sized pool on the seventh floor and a roof, everything changed and we had to go back and reinstall almost another system to give the coverage that they were looking for – that’s quite normal.”
Construction companies’ requirements can be sophisticated, and Phillips cites the Crossrail project. “They needed multiple repeaters, more sophisticated infrastructure because they needed to cover a larger area. And because there was a mix of inside and outside areas, all the equipment needed to be housed in IP-rated cabinets.” He notes Brentwood doesn’t use leaky feeder cables to provide coverage for underground construction sites such as Crossrail because requirements change quickly and coverage is often required at short notice. This plays to repeaters’ strength as they can be moved around and quickly deployed, while leaky feeder cables have to be attached to the tunnel walls.
He adds that Brentwood quite frequently provides systems with multi-site links, explaining that this is mainly driven by the users’ operational requirements. “For instance, when we installed a radio system at the Battersea Power Station site in London. It’s three sites – the construction guys on each site will still need to talk to members of the team on the other sites in the same location. We installed a Linked Capacity Plus system, which meant they could have simultaneous conversations and the system could find a free channel.”
Phillips says Brentwood deploys more lone-worker solutions than man-down systems, with the former consisting of an arrangement in which radio users are required to key the PTT button at preset intervals, say every 15 minutes, and if they don’t then the radio will send an alert to another radio, or a text to a mobile, or an email – “it could be anything”. Once someone acknowledges the alert, they can open up the audio on the lone worker’s radio so that if they have fallen and can’t reach their device, they can shout for help and be heard.
He adds that a lot of flat development projects require crane and crash radios, and many crane operators ask for hands-free systems, which are typically mobile radios with a PTT button either “on the bit they hold or where they steer the crane”, or by using a foot pedal to key up. The operator will talk into a gooseneck microphone, and this arrangement allows them to talk without taking their hands off the steering wheel, so they still operate the crane safely. “It’s very popular and once people have seen it, it sells itself,” Phillips adds. Cranes’ height means it is important to use downward-firing antennas so the signals aren’t potentially “boosted halfway across London”.
Phillips explains that a crash radio is one placed within the crane cabin to be used in the event of an emergency, to tell people to stop or to highlight a problem.
Another very popular health and safety feature for construction sites are emergency freeze or stop buttons. “There could be five or six of these buttons placed across the site and basically, if pressed, they will set off an enormous alarm to everyone onsite – [everyone] has to physically stop what they’re doing. It means that something terrible has happened or someone has spotted a potential danger. The alarm for instance in a crane would be a bright flashing light, it could be audible; it’s a health and safety feature across construction sites.”
When it comes to two-way radio handsets, “because they are going to be used outside most of the time in very harsh conditions, there is a minimum specification that we’d always recommend, we’d never go for the low-end radios for construction sites, because they generally come back caked in mud. IP67 is a good start.”
Phillips adds that in contrast to some other sectors, construction companies have “big blokes with big fingers and they’ve got to find the buttons, they don’t want a little radio, they want something they can grab hold of and can’t be lost easily”.
He says a lot of customer decisions around which handset to use in this sector are based on aesthetics and notes that a lot of “sites won’t place an order unless they see the [radios] working”, so often Phillips and his team will do a “mini-install with a repeater and an antenna and walk around with some radios to prove that they will get coverage across the sites”.
Broadband for the building trade
Thus far, we have only discussed two-way radio, but that is not the only type of wireless comms being used by today’s construction sites. Some builders need to access digitally stored and curated blueprints, and therefore require a solid broadband connection in the field. There can also be a need to provide Wi-Fi for showrooms and marketing suites.
In addition, “A core part of the Considerate Constructors Scheme is to encourage construction sites, companies and suppliers to raise their standards in how they provide a supportive and caring working environment,” says the Scheme’s chief executive, Edward Hardy.
“As such, the Scheme encourages the industry to adopt the latest technology to help improve standards of safety in carrying out work. There are numerous best practice examples of how the industry is utilising Wi-Fi, which are all available on the Scheme’s free online resource, the Best Practice Hub at www.ccsbestpractice.org.uk.”
According to Lee Garrett, technical lead at Westbase Technology, a distributor of 4G LTE networking solutions, one of the biggest challenges in providing broadband to construction sites is that “they could be in the middle of nowhere”. Getting a fixed line can take 30 days, rising to 60 or 90 days in some cases, depending on the site’s location and its proximity to the nearest exchange point.
However, cellular technology (such as the move towards LTE-Advanced) and the quality of MNOs’ networks have progressed to the point where a mobile broadband connection can meet a site’s connectivity requirements, cutting costs and allowing deployment within days, rather than weeks or months.
He adds that the commercial arrangements can also be more flexible than with a fixed service, with the option to have a rolling contract. Even when a fixed-line connection is installed, the wireless system still provides value, acting as a back-up to the main connection and removing the need to order a second line.
The art of antennas
Garrett says that antennas can be a “make or break” for the customer experience when it comes to wireless broadband, and advises that the distance between the antenna and the 4G router is kept as short as possible to minimise signal loss. “One challenge for construction sites is that you have some restrictions on being able to affix an antenna to a cabin, such as not being allowed to drill holes, so using an antenna with suction caps, placing the antenna on the inside of the window, or simply on the outside of the window and bringing in cables through a vent, is a huge enabler, especially as a Portakabin is a bit of a Faraday cage.”
He adds that the results of a site survey will indicate whether an omnidirectional or directional antenna is the best choice. He adds that the former is typically the best approach. If the signal strength is very week, perhaps due to scaffolding, tower cranes or woodland, the installer should “run the antenna as high as possible, but still factoring in that cable distance, and then you can start looking at options for directional antennas and really focus the gain of the antenna to the neighbouring transmission cell”.
Matt Sutton, product manager at Tardis 4G, says that because his company is network-agnostic and can offer sites access to the mobile network with the strongest signal, “all the antennas we provide are omnidirectional. We’re quite proud of the fact that we can provide any network on the same data value for the same price. So, rather than being commercially driven to provide a [particular] solution, we’re performance-driven.”
Plug and play
Sutton adds that while dongles might suffice for one person, “if you have more people onsite, dongles typically fall out, particularly if you’re trying to download blueprint drawings”. Sutton also says Tardis 4G’s router has been designed to support 30 devices simultaneously, and part of the rationale behind this is the sector’s growing demand for data. “As recently as a year ago, we were putting boxes onsite that might have used 20, 30Gb per month; now the average data usage is more than 45Gb per month, and that’s for a site team of four to five people.” He adds that some of the large developers attribute the increase in data use to the fact that the systems being used previously couldn’t cope with sending over 2-3Gb-sized blueprints.
Both Tardis 4G and Westbase’s customers provide plug-and-play systems that are pre-provisioned. As the number of sites supported by a construction company’s IT department can be a challenge for them, Garrett recommends “ensuring that the solution that’s implemented can be remotely managed”, eliminating the need for engineers to make site visits.
Garrett highlights the need to plan ahead when it comes to capacity. “I’ve seen solutions being specified just for day-one connectivity; that might be for 10 users initially and it’s grown within a very short period to 20, 30, 40 users. A solution specified for 10 users is never going to be capable of supporting three or four times that number of users, so be sure to future-proof and implement hardware that has future capacity [requirements in mind].” He adds that Westbase works closely with Cradlepoint, and some of the latter’s products allow extra 4G modems to be added to a router out in the field, allowing customers to grow the solution in line with their onsite team.
Given the construction industry’s increasing reliance on wireless comms, it will be interesting to see whether it embraces the new technologies on the horizon, such as augmented reality. In the future, perhaps construction workers will see wireframe versions of the parts of the building they have yet to build, removing the need to consult blueprints. However, these use-cases will still depend on a rock-solid wireless connection and well-placed antennas.
