Adapting electric buses for airport use

Airport shuttle bus

Adapting electric buses for airport use

When

2024

Client

Swissport

Team

My role

I was the engineering lead for an airport shuttle bus project, with a total of 16 buses delivered to Swissport for use at major airports around Australia. Within the team, I compiled customer requirements, led design reviews, and maintained the Bill of Materials used by our procurement and operations teams. Where possible, I supported our mechanical engineers to enable timely completion of the design phase.

Most of my time was divided between that design work, managing documentation, and ensuring the procurement and workshop teams had everything they needed to build the buses to spec. Once parts started arriving and buses neared completion, I also took on quality control inspections of incoming parts and completed buses.

photo of the bus interior, showing a large luggage rack on the right-hand side
Final design as built and delivered, with two luggage racks over the front wheelarches and conventional seating elsewhere.

Specifications and other documents that I devoted a lot of time to can’t be shared here. However, I can highlight some areas where I contributed (and those are also readily observed by anyone taking a trip to the airport).

Pre-sales support

In the year leading up to contract finalisation, I provided pre-sales support to Nexport’s commercial team and met with the customer on several occassions to work out their needs and finalise technical specifications.

Interior 3D render of the bus shown above. It features luggage racks and sideways mounted seats
3D render prepared for the tender process. This iteration features a near-final design of the luggage rack on the right-hand side and a series of flip-up seats that could increase standing space when required. The final build (shown above) opted for more conventional seating.

Rooftop beacons lights

Because these buses have to abide by airport-specific regulations, I specified fitting a set of rooftop beacon lights near the front and rear. We could not fit the front beacon directly to the roof due to a bump in that area, so our production supervisor requested an additional bracket to be designed. I took that as an opportunity to hone my sheet metal design skills in SolidWorks.

technical drawings in black and white, with an annotated flat pattern shown on the right, and 3D representations towards the top-right
Compilation of technical drawings for a bracket that would allow the beacon light to be installed in the desired location by clearing a hump on the roof itself. The flat pattern layout on the bottom-right looks busy but suppliers could work from a digital drawing to directly lasercut the pattern.
Left: initial prototype made in house, using an earlier, simpler drawing. Middle: First article from the supplier during its assembly. Right: final install on top of a bus, with the hump visible.

Interior passenger information system

Our customer required an internal passenger information system that would show the next stop and announce this over the speaker system. I worked with the system supplier to get a suitable configuration within the allotted budget. This left me with the question of mounting the two interior displays. My intention was to design a simple bracket that would allow the displays to fit over the aisle without exposing its cabling or otherwise intrude into passengers’ headspace. I also wanted to stick to materials and finishes we already used for other components made by our supplier.

handdrawn sketches showing several ideas being explored, with one idea marked in light pink
Some early ideation sketches. I aimed for a minimal number of parts, with the centre-top sketch showing a single folded piece. Unfortunately, that would not allow me to hide the cabling and thus avoid vandalism. Later on, I added the small sketch highlighted in pink, using three welded parts. This was developed further as shown below.
split image of a technical assembly drawing on the left and the real world item on the right
Assembly drawing on the left, with the exploded view calling out individual parts. First test fit shown on the right.

As part of the design process, I checked that the first fabricated part matched my drawings and was suited for its eventual purpose. I also made sure it could be assembled and installed without major concerns, and documented the right procedure for QA/QC purposes. After an early test fit, I worked with production staff to fit all cabling in and determined the easiest way to put it all together.

Details of the first article, made of linished 304 stainless steel. In the middle, some distortion is visible around the interior cutout due bending nearby. During my assembly test, I also realised that slotted holes, at least on one side, could make the install more resilient against build variations of the existing bus structure.
on the left, a test setup of a bolt set in a vise with two stripped bolts shown beside it. On the right, a photo of cabling being fitted with a protective conduit glued and cable-tied to the bracket.
The assembly is fitted with M8 toggle bolts into an existing extrusion on the ceiling, but no clear wrench torque figures were available. So I did some destructive testing to see how far we could take things. Some bolts may have been harmed in the process... On the right, cabling getting fitted and tied down to minimise rattling later on.
two photos inside the vehicle, showing the display mounted close to the ceiling
Final install on the vehicle. Quite pleasing to see the slim profile mostly disappear from view, keeping the focus on the passenger info. Despite the small size, the bracketry hides all cabling from view without making future maintenance harder than it needs to be.

Outcomes and reflection

This project proved quite the challenge for two reasons. First, time available to design and revise was limited because of tight delivery deadlines. Second, as an organisation we had some ways to go in developing efficient ways of converting a design proposal into a built product, with significant effort required in taking the engineering design and turning it into a Bill of Materials that was easily understood internally and by suppliers. With limited established systems, processes, and templates, I in particular had to cover quite some ground getting the info right for other departments. It proved a very valuable lesson though, highlighting clear areas for improvement.