In 1860, the Metropolitan Railway Company of London decided to build a train tunnel under Euston Road at King’s Cross.
The solution, which chief engineer John Fowler came up with, was to simply dig it up, and so Euston Road was shut for two years.
If this were to happen with all train lines, it was projected London would become a “temporary” excavation for the next 60 years. It was obvious a new approach was required. This led to some clever engineers of the day devising the Tunnel Shield method, which allowed the rest of London to continue being a major city while the tube network was constructed underneath.
Whilst there is often an obvious way to achieve something, it is not always the best way.
This is true with live operating hospitals. As engineers, the way in which we achieve the required outcome is paramount. More often than not, the critical factor is to design for minimum impact on the core operations of the existing hospital. At the heart of this is maintaining hospital beds – they bring in the revenue, and they perform that vital role for the surrounding community.
As part of the early works prior to the major campus redevelopment at Box Hill Hospital, the operating theatres in the 70-year-old North Wing desperately required brand new plant equipment upgrades. Access, however, was impossible.
Operations were being performed in the North Wing, the West Wing is a live hospital ward and, meanwhile, babies were being born on the ground floor in Biralee House.
The obvious and easiest solution was to take the John Fowler approach and simply shut down the operating theatres for four weeks, rip the ceilings out, decommission the old equipment and replace it with the brand new technologies.
Of course, Box Hill Hospital couldn’t fathom the thought of operating theatres being knocked out for four weeks. The entire process needed rethinking.
By positing large beams between the two, separate existing brick buildings, a bridge was created forming an external plant platform up at this level so that all the new kit could be installed while the hospital remained fully operational.
A construction sequence drawing was developed which showed how the lightweight roof was to be protected with plywood during construction. Little things like positioning a lightweight aluminium scaffold two metres from the edge demonstrated how this would facilitate installation of the platform from the outside, with no access through the wards required.
In addition to this, a hanging walkway was built at the lower level. The existing roof over the birthing suites was not strong enough to take the load and the ability to put columns through here was just not appropriate. The steel structure was designed for quick installation using a mobile crane with minimum noise and vibration disturbance. It also created a new access connection which could be utilised to transfer mental patients, negating the need to use ambulances as was previously required.
Connecting big steel beams to 70-year-old existing brick walls is not a simple task. Typical connections were complex because differential movement between the two buildings had to be allowed for.
The beauty of this solution, despite the potential headaches for engineers and builders, was less the final engineered outcome but more the way that it was designed. It allowed all the construction activity to take place while babies were being born and the operating theatres were only down for one weekend rather than the four weeks if the obvious, simple path had been trod.
At Warringal Hospital, similarly, emphasis was on the ‘how’.
Foresight in the design phase will hopefully pay big dividends in the future, with the capacity for three future floors to be added down the track. Instead of just stopping at designing the columns for the additional load, as would be typical, however, holistic consideration was given to the occupational health and safety issues around major construction work over a functional hospital building.
The solution is a roof slab to act as a future construction deck; designed for a 20 kPa live load rather than a traditional roof load of three kPa. The cost-benefit analysis showed that while there was a small increase in the initial capital cost, the long-term time and cost benefits would be outweighed by this future proofing.
Much of this future planning and strategy can and should be teased out before much design work is carried out.
Epworth Rehabilitation Hospital is another case in point. A conglomerate of old brick buildings has been transformed into a brand new facility, which opened last year. But what you can’t see from the unassuming street view is the enormous three-storey basement car park excavation below.
The site was pushed to its limits by digging out the maximum possible footprint, hard up against the existing hospital on 2 sides and the main roads on the other sides.
It certainly wasn’t the easiest approach, especially when significant amounts of rock were encountered, but it was worth it for the subsequent benefits.
Of primary benefit was again minimising impact on key hospital operations.
The physiotherapy department, which included a pool in this case, is crucial to any rehabilitation hospital. The bored pier system allowed the massive hole to be dug vertically right next to it without affecting the department’s daily activities.
For no additional cost to anyone, by arranging the retention wall system in the basement it will allow an easy connection to the future expansion of the hospital with just a simple cut.
And, of course, major car parking problems at the hospital are now a thing of the past.
A final example is at Monash Children’s Hospital in Melbourne where a three-storey extension, incorporating 24 new beds including an intensive care unit, was built over the existing single storey main entrance of the hospital.
The way it was designed made all the difference.
Here, the hospital entrance remained functional by stacking new columns directly over the existing columns, and utilising composite steel construction for minimum weight to enable the fastest construction time frame. The tired old existing entrance has now been dressed with a new canopy and a double storey curtain wall to deliver a welcoming experience.
These four very different approaches but all demonstrate how smart design solutions can keep core operations running at all times. It is this ‘minimum disruption option’ that more and more hospitals are demanding.