Black Rock Clinic -Prefabricated Plant Room

BRC Plantroom, Blackrock Clinic

How Hayes Mechanical & Engineering turned one unusual design decision into a cross-country feat of steel.

Most package plantrooms are built to be light. A slim steel-decked floor keeps the module easy to fabricate, easy to move and easy to lift. So when Hayes Mechanical & Engineering (Hayes M&E) was engaged by Titanium Developments to design, fabricate and install a prefabricated steel plantroom for Blackrock Clinic in Dublin, the brief came with a twist that changed everything: the floor had to be concrete.

This was not a detail. Blackrock Clinic is a busy, fully operational private hospital, packed with sensitive diagnostic and clinical equipment. Vibration from rotating mechanical plant — pumps, fans, the air handling unit — can travel through a lightweight floor and into the building around it. The answer was to build the module on a 110 mm composite concrete slab, cast on Kingspan MD60 metal decking and bonded to the steel frame with shear studs. The mass and stiffness of that slab tune the floor's natural frequency, shifting it away from the plant's operating frequencies and bringing the module's dynamic behaviour into line with the host hospital. In short: instead of fighting vibration, the design engineers it out at source.

It was an unusual, forward-thinking call for a package plantroom — and it became the engineering heart of the whole project.

Good engineering has consequences. That concrete floor added the better part of eleven tonnes, taking the finished module to roughly 28 tonnes. A job that might have been a routine modular lift became a genuine heavy-lift and abnormal-load undertaking — and every challenge that followed flowed directly from the decision to do the dynamic engineering properly rather than take the lightweight shortcut.

Hayes M&E took ownership of all of it.

Built complete, in Mayo

Rather than ship loose steel to be assembled on a congested hospital site, Hayes M&E built the entire plantroom at its yard in Ballintubber, Co. Mayo. The primary and secondary steel frame was fabricated to Execution Class EXC2 under EN 1090-2, braced with CHS 114.3×5 mm members and topped with purlins deliberately set to fall toward the roof outlet. The composite concrete floor was cast into the frame. And crucially, the module was fitted out as a working plantroom before it ever left Mayo: Hayes M&E installed the air handling unit, ran the associated pipework, and clad the unit in 45 mm Kingspan louvre panels in Obsidian Grey (RAL 9007), with a 150 mm AWP-S fire-rated panel, AHU intake and exhaust louvres, parapet and drip-rail flashings, and a 60-minute fire-rated door.

The result that rolled out of the yard was not an empty steel box. It was a complete, weather-tight plantroom — off-site quality, ready for on-site speed.

250 kilometres, overnight

Then it had to get to Dublin. A 28-tonne, fully fitted module, tall and heavy, is an abnormal load in every sense. Hayes M&E moved it roughly 250 kilometres across the country, overnight on a low-loader, through route assessments, structure and bridge clearances, permits and escorts — a single, carefully choreographed delivery onto a tight, city-edge hospital site, with no margin for error and no second chance.

A lift engineered from scratch

A module of this mass cannot simply be slung and hoisted. Hayes M&E designed, fabricated and certified a bespoke temporary lifting arrangement — four lifting beams in 152×152×37 UC, distributing the load across eight points so the module stayed dead level and its permanent steel was never overstressed under the reversed, lift-induced loads. The arrangement was independently appraised by SDS Engineers and the temporary works certified, with comfortable margins retained throughout. On the day, a Liebherr LTM1650-8.1 lifted the module clear over a working hospital and set it precisely onto its pre-installed stubs, to a fully developed lifting plan and a competent, LOLER-compliant lift team.

The most constrained site imaginable

If the engineering was demanding, the site was unforgiving. Blackrock Clinic is a dispatch point for radioactive nuclear-medicine material, which leaves the campus on a fixed schedule three times every single day. Each dispatch stopped the works dead — crane and lifting operations included — carving several slots out of every working day. Next door, a school was sitting examinations, ruling out noisy operations at the wrong moments. And on every side, a live hospital had to keep running: patient access, ambulance routes and clinical activity protected at all times.

The genuinely usable working window each day shrank to almost nothing. Hayes M&E planned around the embargoes, sequencing the heavy lift, the in-situ erection of the link corridor connecting the new plantroom to the existing building, and the final fit into those narrow slots. The link steel went up using a compact spider crane suited to the restricted access, with powered access platforms keeping people safe at height. And still — against the radioactive timetable, the exam embargo and the live-hospital choreography — the programme held.

Small package, serious project

Measured by footprint, this is a small job. Measured by content, it punches far above its size. In one compact module, the project brought together genuine dynamic-design thinking, full off-site fabrication and mechanical fit-out, bespoke heavy-lift temporary works, cross-country abnormal-load logistics, and a safe, precise installation on one of the most constrained sites a steelwork contractor could be handed — all delivered at pace.

Hayes M&E didn't build the easy plantroom. They built the right one. From a yard in Mayo to the heart of a Dublin hospital, the BRC Plantroom is a reminder of what Irish steel — and an Irish team willing to own every consequence of doing things properly — can carry.

Project: BRC Plantroom, Blackrock Clinic, Dublin · Client: Titanium Developments · Steelwork contractor: Hayes Mechanical & Engineering Ltd · Standard: EXC2 to EN 1090-2 · Module: ~28 t, 110 mm composite concrete floor · Lift: Liebherr LTM1650-8.1, bespoke eight-point arrangement.