The Royal Engineers have designed and delivered emergency infrastructure to deal with the Ebola outbreak in West Africa.
The West African country of Sierra Leone had made considerable progress in education, healthcare and governance since the end of its brutal civil war in 2002. However, the recent Ebola outbreak posed a severe new threat and raised fears of a global pandemic, prompting a UN Resolution and calls for international assistance.
The Department for International Development led the UK response, working with the government of Sierra Leone to contain and treat the disease. One key strand of the strategy was the construction of six specialist Ebola Treatment Units throughout Sierra Leone, to be operated by international aid workers and volunteer NHS staff. In late September 2014 a group of Royal Engineer specialists from 62 Works Group were rapidly deployed to design and deliver the emergency infrastructure.
When the Royal Engineers arrived in West Africa a small number of emergency treatment units had already been constructed. However these were very basic and suffering from appalling levels of infection amongst healthcare workers. Design of the treatment units was therefore driven by the epidemiology of the disease and the need to ensure clinical safety of the volunteer operators and staff.
The primary consideration in the design is “patient flow”. As Ebola patients deteriorate they become increasingly contagious, patients must only ever move through the units in one direction in order to prevent the spread of contamination. Staff, in full protective equipment, only ever follow the same path and require rigorous checking and decontamination on entry and exit.
A range of local contractors were employed to build the units and as the contract details were being completed the military teams established forward operating bases in three remote towns. The Royal Engineers worked closely with the contractors to accelerate programmes and tailor construction methods to the specific capabilities of each workforce. The Royal Engineers worked as the designer and client’s representative, but this role ramped up massively, stepping into direct construction management and hands on construction as required, filling shortfalls and accelerating work. Republic of Sierra Leone Armed Forces personnel were also involved in the projects, with the infantry providing security and engineers providing low skilled artisan manpower.
Disaster relief tents on washable concrete pad foundations were used for many of the main structures, but at concept design stage there was much discussion about the best structural form for all the ablutions and secure buildings such as the pharmacy, laboratory and mortuary. Both block and timber options were developed, but experience showed that blockwork could be erected extremely rapidly, to a relatively high quality, and would leave a useful legacy for the local communities.
Plans for the mortuary were enlarged twice during design as predicted fatality rates grew. Corpses of Ebola victims are extremely contagious but washing the body of a family member prior to burial is a key ritual in Sierra Leone culture. In order to avoid unauthorised contact with the bodies a covered viewing platform was therefore added at the back of each mortuary, with a double fence to allow relatives to watch medical workers washing a body before it is taken for burial.
None of the remote sites had an existing water supply therefore boreholes were constructed to fill on-site storage tanks. Chlorination tanks are then used to supply three completely separate water distribution systems providing raw, low chlorine (hand washing), and high chlorine (disinfectant) throughout the site. Waste water is handled in two completely separate systems; one for the high-risk “Ebola” zone, and one for all other areas. The construction of traditional reinforced concrete septic tanks risked delaying the project, so a number of innovative alternate designs were developed using locally available products.
While the construction of the treatment units produced many interesting challenges, the most urgent engineering task turned out to be the repair of a critical bridge, the loss of which would have severed the country in two. Travelling to site the Royal Engineers spotted that one of the end diagonals of thesteel trusses through the bridge had suffered severe impact damage where it had been hit by the blade of a bulldozer on a flat-bed. While the original bridge could withstand the load of a 120t vehicle, the damaged section was over its design stress due to self weight of the bridge alone and starting to bend out of plane. It was assessed that a 50t lorry was likely to cause immediate collapse. The Royal Engineers produced a design and the government of Sierra Leone approved an immediate repair. The Department of International Development paid £6,500 for the work and within 96 hours of the damage being spotted the bridge was repaired.
Laboratories are crucial in fighting the spread of the disease, enabling positive cases to be confirmed and isolated and negative cases to be released from high risk containment areas. Versatile laboratories were quickly designed and constructed, and within three weeks Public Health England clinical staff had them running on temporary power and water supplies, receiving samples while work continued across the rest of the sites.
The construction of treatment units was just one small cog in the process of getting victims out of their communities and treated. The mountain of medical equipment and supplies started arriving at the sites and a staged process of “beneficial occupancy” was managed to allow the brave clinical staff to start training and rehearsing. The first patients started arriving about four days after the contractors left site.
While projects of this scale typically take several years to plan and deliver, the exponential spread of the disease required that the design, tender, and construction programmes were extraordinarily accelerated. Full detailed design was completed in eight days and the full and compliant tender process was completed in less than two weeks. Extensive innovation and gruelling work programmes ensured that all six treatment units were operational less than three months after their need was identified.
At the time of writing this article it appears that the combined efforts to defeat Ebola have been successful, with deaths in the low thousands, rather than the millions predicted. The battle now is about eliminating the disease completely, the treatment units will continue to play a vital role, isolating and treating new cases and thereby enabling Sierra Leone to develop.