TowerXchange: Please can you introduce Allied Consultant Engineering to TowerXchange readers?
Roger Murphy, Director, Allied Consultant Engineering (ACE): Allied Consultant Engineering (ACE) was established in 2015. We provide structural engineering expertise, to ensure the safe and economic utilisation of existing telecommunications infrastructure. Our goal is to be smart, flexible and competitive in the telecommunications sector.
To date ACE has assessed and designed tower upgrades in Australia, Ireland, the UK and Spain. Some of our key clients include Axicom (Australia), Axion (Spain), ESB Telecoms (Ireland) and Towercom (Ireland), as well as other tower owners and MNOs in the UK, Irish and Australian markets.
We are based in Dublin, and have a second design office within the Republic of Ireland. As well as myself, the team includes specialist structural engineers, design technicians and administrative support. We have strong ties to academia, and we have conducted tower health monitoring R&D projects with Trinity College Dublin.
The services we provide can broken down into two categories:
- Structural assessment and upgrade designs of existing wireless infrastructure.
- Helping tower owners understand their structural data.
TowerXchange: Can you describe the structural data offering in more detail?
Roger Murphy, Director, Allied Consultant Engineering (ACE): Our consultancy service focuses on helping towercos improve the value of their portfolio.
Most towercos possess a wealth of structural data. The challenge is often making sense of that structural data to inform strategic capacity decisions. Making sense of the data can be done without the need for expensive software or bespoke platforms. Unlocking this deeper understanding of your portfolio will make it clear where the risks lie, and the capacity opportunities exist.
Once the existing data is properly understood, process improvement will follow. In particular the structural upgrade process can be streamlined. For every project, in every tower company, the structural upgrade process has a defined start point, execution phase and completion point. The complexity of each upgrade is different, but the process can be controlled. We use our experience with structural upgrades to help tower owners step back and take some of the pain out of the structural upgrade process.
Ultimately, every tower company has a unique portfolio, and a unique team. We can tailor our consultancy offering to suit.
TowerXchange: Where is the majority of work focussed for Allied Consultant Engineering at the moment and what is driving this? Do you see this trend continuing?
Roger Murphy, Director, Allied Consultant Engineering (ACE): Without doubt, the accommodation of 5G on existing infrastructure is the majority of our work. The rollout of 5G networks is driving this trend, and industry is increasingly understanding the value of getting structural engineers involved in the early stages of site design.
Existing infrastructure is a very broad term of course. The traditional vertical infrastructure of towers, masts and monopoles need continual optimisation and upgrade to cope with the demands of 5G equipment loading.
Increasingly we see a higher proportion of rooftop and non-standard structures being developed, and we certainly see this trend continuing due to the nature of 5G technology. In the past 12 months an increasing number of our projects have involved assessing rooftop and non-standard vertical infrastructure. The assessment of existing buildings will become increasingly important throughout the 5G lifecycle. Structural engineers within telecoms need to be able to appraise older structures, and broaden their ability to understand materials other than steel and concrete.
The reality is that our broad range of expertise and experience means that ACE can learn from each project and apply that knowledge to new clients. This means that as we progress through this period of 5G integration we are always ahead of the curve. Consequently we are able to reduce the complexity of the structural service proposition.
TowerXchange: Do you see the move from 4G to 5G as a bigger step change in wind load/ structural design than 3G to 4G?
Roger Murphy, Director, Allied Consultant Engineering (ACE): Definitely. Antenna configurations are becoming more optimised. The wind loading aspect is becoming more intricate, due to optimised configurations. Aside from the telecom industry drivers, the second generation of Eurocodes are in development. I sit on the Technical Committee for both the wind loading and tower Eurocode standards, and it is clear that the second generation of Eurocodes will bring changes in how we assess tower infrastructure. These changes will begin to effect the wider industry in 2022.
Eurocode developments will also effect rooftop and non-standard sites considerably. Currently a new Eurocode on the “Basis of Assessment and Retrofitting of Existing Structures” is in development. This standard will be particularly important to owners of existing infrastructure.
The structural design aspect will be a more significant step change.
For rooftop and non-standard sites, there is a huge design challenge. Densification of cells means rooftops and non-standard structures will form a higher proportion of sites, and accurate appraisal of rooftops will become increasingly important. Collaboration with other disciplines is critical in delivering successful outcomes. Structural engineers must be aware of the implications of their design decisions, and keep lines of communication open with a range of stakeholders including projects managers, construction contractors, property professionals, radio engineers and town planners.
ACE is acutely aware of this need to keep the wider user base and supply chain properly engaged. This engagement avoids problems at the late stage of a site upgrade coming from uninformed stakeholders.
TowerXchange: Do you see different attitudes amongst Europe’s tower owners in terms of the type of fix they are looking for (e.g. minimal upgrades vs future proofing for extra capacity)?
Roger Murphy, Director, Allied Consultant Engineering (ACE): Yes we do see different attitudes. Some owners are starting from a point of high capacity structures, and some are not. The historical starting point of their portfolio tends to colour their thinking.
The decision to future proof an existing tower is difficult. There are many competing parameters involved including; customer requirements, environmental loading, cost of upgrade and property constraints. For any given site it is possible to devise a high-level concept design for future proofing that can be priced. This concept design can then be developed fully when it is needed.
This approach has two key advantages; Firstly, tower owners do not have to commit CAPEX to upgrading sites where demand is lower than expected. Secondly there is adaptability if customer requirements change and increase. Our view is that future proofing should be looked at on a site by site basis, not as a blunt policy of “let’s make sure every tower is at 90% capacity”.
TowerXchange: Whilst each tower is different, what do you see as some of the key ways to reduce the cost of structural upgrades?
Roger Murphy, Director, Allied Consultant Engineering (ACE): For any upgrade, costs can be controlled by ensuring accurate structural data is available. Structural engineers are bound to make conservative assumptions when information is missing. The less information that is missing, the less conservative assumptions will be made.
As a tower owner, there are many options available to reducing the cost of structural upgrades. The most important thing any asset owner can do is manage their structural data properly. Unfortunately, it is very common that original as built information is patchy or non-existent. Consistently doing simple things such as chasing existing drawings and reports can significantly reduce costs across a portfolio.
For major upgrades, the cost reduction process is more involved. For arguments sake, let’s define a major upgrade as a structural upgrade costing over Ђ70,000.
In the case of major structural upgrades, a good analogy is performing major surgery on a human patient. Major surgery is only considered if there is a serious health problem.
If a serious health problem is suspected in a human, you need to be sure that major surgery is the best option. For towers the same is true. Before deciding to perform a major upgrade, the structural engineer needs to be satisfied that the upgrade is necessary, and options to reduce the scale of the intervention on the structure should be explored. Sometimes an expensive design concept becomes accepted within an organisation before all the facts are available.
A deep dive of the structural assessment should be undertaken to find any loading reductions that are safely possible. In many cases, structural health monitoring of the tower should be considered. The predicted behaviour of a tower in a computer model will not be exactly the same as the real-world physical behaviour. We have applied structural health monitoring techniques previously and identified additional capacity for tower owners.
The reasons for reducing the extent of structural upgrades are not only economic. As with human surgery, major upgrades are not without risk. Major upgrades carry the risks that are always associated with construction projects. Adding remedial steelwork adds wind loading and weight to towers, which is a further risk. Adding steel is not the only way to verify the structural safety of a tower. Sometimes less is more.
