Padraig Moloney: Keeping boats moving

For Padraig Moloney, a boat ramp repair he saw on a childhood holiday sparked his interest in marine infrastructure.

Padraig Moloney

The senior maritime engineer at AW Maritime studied civil engineering at University College Cork in Ireland before specialising in marine engineering thanks to a particularly influential professor. 

Today, he still finds the combination of sea air, steel and concrete a heady mix that continues to inspire his work. We caught up with Padraig to talk about what it takes to build the piers, jetties, boat ramps, harbours and docks that keep our recreational and commercial vessels moving.  

What does a typical day look like for maritime engineer?

One of the best aspects of my career is that there are no real typical days and I get to travel a fair bit. For example, last year I spent quite a lot time down the Great Ocean Road inspecting Lorne Pier and coastal protection structures in Warrnambool and Port Fairy. It’s magic country. 

To be successful in the field, we need to prepare equipment, boats and potentially divers. We also need to monitor the weather and tides, so they are favourable, and in the end, we are completely immersed in the environment completing our work. On sunny calm days, it is a pleasure. On cold winter days, it can be punishing. 

When I am in the office, you’ll find me developing a design, drafting construction drawings, writing technical reports, or estimating a dredging project. 

How do you go about designing infrastructure in a marine environment?

In many ways, the design is straight forward. At a high level, it is made up of three aspects: the inputs, the process, and the deliverable.

The inputs are basically the definition of the project, as in what are we designing? This aspect can take time, but it’s important to work through all the factors we need to consider when scoping out the job. We need to understand what the design life of the structure is, as in how long it will need to last, what size and types of boats or vehicles are to be accommodated, how busy the facility is, and what materials or configurations are preferred. When a project has multiple stakeholders, it can be difficult and time-consuming to get consensus on these aspects. And, even if consensus is achieved, the outcomes need to be balanced against a budget.

The process is our favourite part of the project. This is where we use the inputs, or basis of design, and then estimate the loads which need to be sustained by the structure and specify the capacity to suit. Some loads are obvious, such as boat, vehicles, and crowds, but there are also environmental loads, such as wave and wind load that need to be estimated and included. The ability of the facility to bear the loads includes both the structural capacity of the elements, for example the concrete ramp or steel pile, and the geotechnical capacity of the site. To estimate the geotechnical capacity, we complete geotechnical investigations that entail drilling or excavating the ground around the site to analyse the sand, clay, rock, or gravels. These investigations can take weeks to complete.

The deliverable is the most nerve-racking aspect of project. This is where we put forward our design for review by the client and stakeholders. The design can be in the form of drawings, reports, and specification documents. The goal is to communicate to a construction contractor what they need to build and to what level of specification. These documents can be very technical, so we usually produce more aesthetic images to convey the ideas to the client or stakeholders.

So, if the inputs are well considered and widely agreed, it runs smoothly. Organisations that prioritise engaging early and openly with stakeholders certainly help clearly define our role and make the process much easier. 

What’s the most challenging and rewarding aspect of designing boat ramp in a maritime environment?

It depends. For some projects, the biggest challenge can be a client with unrealistic expectations and for others, it can be difficult environmental conditions or availability of suitable contractors. As engineers, we are driven by logic, so if the challenge is tangible then we enjoy working out an engineering solution. For instance, when designing a structure, we need to ensure there are construction contractors available who have the right equipment and expertise to complete the work. Or if the site has difficult geotechnical conditions or a lot of wave energy, then achieving a functional design solution is rewarding. 

It is much more difficult to bring someone around if they’re not happy with the project, and very often logic doesn’t prevail if it is not delivered with empathy. It’s why good stakeholder management and communications go hand in hand with successful infrastructure projects.

The best engineering should go unnoticed, so the most rewarding aspect of our work is to see what we have designed functioning in harmony with its environment, like it has always been there.

Do you find the feedback from users helpful in the design process? 

Absolutely. For me to really understand a challenge, I need to get first-hand experience by visiting the site and seeing it for myself. This helps me relate to the end user and design on their behalf. Once I’ve had a chance to observe, my conversations with the end users are much more constructive.

On some remote sites, we may have limited data available on how wave, wind and tidal currents effect the site. In this situation, facility users often have the most comprehensive understanding of all these aspects and can provide valuable insights that will lead to good outcomes and a shared sense of ownership. In fact, I’d think early engagement with end users is essential wherever the project is.

Do you have to approach design according to different marine environments? 

Yes, this is one of our fundamental roles in any design process. We need to evaluate the environmental conditions on any structure we design, as each site has a varied level of exposure to wind and waves, but also a different tidal range. The tidal ranges of Port Phillip Bay and Western Port Bay differ by about two meters, even though the sites may be geographically close together.

There is also a considerable difference in wave energy between the bays and the open ocean sites. Even with some protection, open ocean sites can still experience wave energies with very long frequencies. For us as the designers, it can often be difficult to get reliable wind and wave data so on some projects, we may need to install data loggers to capture site specific information. Although sites can be similar, no two are ever the same.

What approvals are needed when you’re building in the sea and why do they take so long?

The approvals to build in marine environments vary depending on the location and the extent of construction works required to complete the project. The most obvious approval is planning permission from the local council or city authority. This generally relates to the landside aspects of the project, including drainage, traffic, and visual impact. 

The less obvious ones are Marine and Coastal Act consents, Heritage Victoria approvals, Aboriginal Cultural Heritage approval, and works authority approvals from port and waterway managers. While not all of these apply to all projects, they all need to be considered and documented. A project can potentially have more approval requirements if it is located within a special area of conservation site. Generally, all permitting is done at state level with only very large projects requiring federal approvals.

What has been your favourite boat ramp project to work on and why?

That would be much very first and my current project.

The first was on the River Blackwater in Cork – a very beautiful part of Ireland. I was a resident engineer for the client and enjoyed the novelty of seeing the construction project develop. The contractor was quite poor and out of their depth, so as a young engineer it was stressful to keep them on task. I certainly learned a lot and in the end the outcome was good.

My current project is an open coast site in Warrnambool. The site experiences a lot of wave energy, so being able to address this isn’t straight forward. The local stakeholders are very passionate and have been trying for a long time to make some improvements. Luckily, after years of studies and concept designs, it looks like we’re going to get going on the first round works to the port, starting with the boat ramp.