Would you like almost unlimited capacity to add more tenants to your towers?

It’s one of those ideas so simple that you can’t imagine why anyone didn’t think of it before! In the tower industry we all understand that wind load is usually a more important factor than equipment weight in determining the capacity of a tower. Round shapes are more aerodynamic than boxes. So if we mount a light weight, round shield over the equipment on our towers, will the capacity be increased? Tower design and installation wizard Christian Strømme has built a prototype that could revolutionise the tower business.

TowerXchange: Please introduce your revolutionary Tower Shield.

The Tower Shield can enable you to make your towers available to all the tenants you want.

Deploying the Tower Shield will unlock almost unlimited capacity, even on towers designed for single tenants, at significantly lower cost than by upgrading structures and foundations.

The Tower Shield enables towercos to dramatically improve return on investment in improvement capex, and increase tenancy ratios and tower cash flow.

TowerXchange: How does it work?

A round shape has a lower wind factor than a square shape, such as the antenna and other square-shaped parts mounted on a tower. Installing a round shield over the antenna makes a tower more aerodynamic by reducing the wind forces on any equipment inside it.

The prototype we have designed has an EPA of 3.6sqm, is 3m high with a radius of 2.4m, and has capacity to enclose up to 12 to 16 antennas (depending on the size) inside the shield. But the Tower Shield is designed to be a modular solution, so the shield specification can be adapted to suit the tower, and more shields can be added according to the amount of equipment to be hung on the tower.

The Tower Shield is made of light but strong material which allows signal to pass through without being disrupted. We use a 7mm sandwich laminate GRP – the same material radar domes are made from – which means we are able to achieve a signal loss of less than 0.3 dB.

The Tower Shield complies with the ANSI/TIA-222-G American design code, EN1993-3-1 and EN1993-3-2: Eurocode 3, European codes.

TowerXchange: How would the Tower Shield be installed and mounted?

The Tower Shield can be easily mounted on the outside of a tower with clamps. Each part is about 60kg, so it’s a quick and easy installation – easier than adding an antenna.

TowerXchange: It sounds almost too good to be true. How have you proved the concept?

We have just completed construction of a prototype in Beijing, from where it will be shipped to be unveiled at the TowerXchange Meetup Africa in Johannesburg on October 3 and 4.

TowerXchange introduced us to some potential customers at their Americas Meetup in June, and we’ve also done some calculations for another towerco showing how the Tower Shield could enable a tower designed for two tenants to accommodate four tenants at a site in Southeast Asia.

But Tower Shield can improve the capacity of any tower, anywhere in the world.

TowerXchange: Tell us more about the calculations that revealed that installing Tower Shield could enable four tenants to be accommodated on a tower designed for two.

We examined a tower located in Southeast Asia which had been designed for two tenants and was just about able to support three. The towerco that owned the tower had been asked to co-locate a fourth tenant, for which they calculated that they would need to upgrade the existing structure with 5,000kg of steel and 10sqm of concrete foundation.

We found that we were able to deliver more than enough wind load capacity to accommodate the fourth operator by placing a Tower Shield over just the RDUs and filter boxes of one existing tenant. If a 3m x 3m Tower Shield was installed over six RF antennae, each with an area of around 1m, we would reduce the wind load by a factor of 60%, while the coefficient for the antennas is 1.2, so the Effective Projected Area (EPA) was reduced from 8.4 to 5.4, reducing uplift by 7% and compression by 5%.

Installing a Tower Shield would mean the foundation wouldn’t need upgrading and the addition of just 400kg of steel would bring the tower within reasonable range.

TowerXchange: That’s a great example of upgrading an existing tower. How can Tower Shield transform the economics for new build towers?

We spoke to one of the Directors of a leading towerco in Indonesia who shared a common challenge that other towercos will recognise: whether acquiring an existing tower or building a new tower, it is difficult to predict whether and when there will be demand for capacity for a second, third or fourth tenant.

As a result most towercos (and an increasing number of MNOs) have designed and built new towers with capacity for two tenants. With Tower Shield you can now use low cost, lightweight, single tenant structures for all new builds, minimising capex, therefore minimising risk. All you need to do is pre-install structures with shield brackets, then a single tenant tower can be easily upgraded to accommodate two, three, even four tenants by adding a Tower Shield.

TowerXchange: What is a ‘Top Shield’ and what are its use cases?

A Top Shield can be installed when the load on a tower surpasses its structural capacity due to the addition equipment.

Let me illustrate this with an example. A new tower may have shield brackets pre-installed, but it might not need a Top Shield to be added to cope with the initial load. As new technology rollouts and co-location agreements require the addition of more antennas and dishes to the tower, added in a controlled manner and usually starting from the higher elevations, the tower eventually reaches the point where the Top Shield is needed to reduce the EPA of the existing equipment and free up capacity to add further load. This solution doesn’t require additional reinforcement of either the tower or the foundation.

TowerXchange: How have the towercos you’ve spoken to about Tower Shield responded?

We spoke to the VP of Tower Development at one towerco. He was a structural engineer and promised us a tough cross examination, but the concept is so simple and intuitive that it took him seconds to understand and he didn’t have any questions – he just ran off to tell his colleagues about it!

TowerXchange: What will Tower Shield cost?

Like any tower modification, the cost depends on the specific requirements and dimensions of the tower concerned.

In the example we quoted in Southeast Asia, the improvement capex to upgrade the structure and the foundation to accommodate a fourth tenant would have been in the region of US$20,000. With Tower Shield, we’d anticipate being able to achieve the same capacity for half the price, including shipping and installation.

Of course higher volumes would mean we’d be able to manufacture and sell Tower Shield at a lower price.

We’re also making arrangements such that we will be able to provide one to two years of financing.

TowerXchange: Could customers offset the cost of Tower Shield by selling advertising on the shield’s surface?

Sure thing! Where landlords allow the structures to be painted, logos or marketing campaigns can be added on. We have seen examples of this where similar solutions used for camouflaging the tower and antennas have been used as a billboard.

TowerXchange: What is your background – how did you come up with this idea?

As I’m the third generation of my family in the tower business, I’d love to say this was something I have invented on my own, but its been a team process! Our engineering, supply and sales departments have worked this one out together. The idea of reducing wind drag on the towers has been discussed both at the office and around the house as long as I can remember; but the combination of three recent circumstances has been pushed us to develop this solution.

First, we are frequently asked about upgrading legacy towers by towercos that have recently acquired older towers. We recently had a very detailed discussion with a towerco in Indonesia that wanted to minimise improvement capex, while preserving the potential to make recently acquired towers available for multiple tenants. We investigated re-filling of foundations, easy steel upgrades (adding bracings et cetera), but all the solutions we came up with were either sub-optimal on the saving side or very costly.

Then there was a discussion with a client about extending existing tower structures to accommodate new tenants. Though this is very possible, it eats a lot of the structural capacity, and we were back again looking at how to strengthen towers in an efficient way.

At the same time, we’ve had the oil crisis in Norway, and though this has been damaging for the O&G industry it lead to us getting a new flow of talent from outside the telecom industry, especially on the engineering side. They brought a fresh approach to things and the result was the idea of the TowerShield.

TowerXchange: How can readers find out more about Tower Shield?

To introduce and answer questions about the Tower Shield, we’ll be co-hosting a webinar with TowerXchange on September 27 at 2pm CET / 9am EST – please register here.

Alternatively, come and see Tower Shield for yourself – the prototype Tower Shield will be on display at the TowerXchange Meetup Africa at the Sandton Convention Centre, Johannesburg on October 3 and 4, and at the TowerXchange Meetup Asia at the Marina Bay Sands in Singapore on December 12 and 13!