Knights Brown has won a contract to design and construct the extension of the cruise berth at Portsmouth International Port. This will allow the port to handle ships up to 255m in length and welcome 150,000 cruise passengers each year. With design work already underway, we will be arriving on site in November and in this quick turnaround project, will be finished by the spring.
We have been delivering technically complex projects in coastal, marine and river environments along the south coast for many years. Our practical experience and range of skills were instrumental in helping us secure this high profile contract.
Our Bid Manager, Nick Gibb, says: “We work closely as a team, listening to each expert and finding ways to solve challenges together. Every project meets hurdles and the only way to beat them is to work together. Because we are a business where we can all act decisively, we don’t waste time; we can make decisions and move on. This is great for our customers and getting the job done.”
Examples of where we have deployed skills comparable to those required at Portsmouth include:
• North Portsea Island Flood Defences Milton Common and Tipner Lake
• King George V Dock, Southampton
• West Bay Deep Water Berth
• Pendennis Non-tidal Basin and Wet Dock
In this blog we look at how we will be delivering the new cruise berth.
Design Management & Value Engineering
We work with trusted design partners who we know have the skills and knowledge to match the complexity of the task. Working together from an early stage allows us to use our influence and experience to achieve a practical design solution that can be safely and efficiently constructed on site.
Every project has challenges but we love finding innovative solutions that bring benefits such as a reduction in programme and cost and improved safety and sustainability, by questioning conventional solutions.
Offsite manufacturing for example can enhance a project by:
• Reducing exposure to the hazards of working over, under, or in, water
• Lowering costs associated with using expensive marine plant
• Improving quality by producing components in factory-controlled conditions
At Portsmouth International Port we will be pre-casting concrete units off site, which will guarantee the quality of the concrete, while also allowing the units to arrive on site ready to place onto the piles. This will be quicker and more cost-effective than casting concrete on site. The ‘dolphin’ structure to support the new pier will also have a prefabricated carousel.
We have also looked at reusing structures wherever possible. In the original specification the relatively new, dolphin structure was going to be removed but we could see potential for it to be incorporated into the new berth arrangement. We’re now examining other structures and investigating the thickness of the steel, to see where they might be strengthened and reused.
All of this will achieve better value and be a more sustainable and responsible approach.
As we will be working in a marine environment, we will be taking extra precautions to protect the local habitat and manage impacts on the location. Site surveys will ensure we are prepared with as much information as possible, all of which will be used to inform our design and de-risk the construction phase.
This includes surveys for:
• UXO, to identify any unexploded ordnance within the footprint of the site.
• Ground investigations, to determine the optimum pile design prior to driving a borehole into the seabed.
• Topography, so structures can be accurately incorporated into the design.
Working in Portsmouth International Port
The port will remain fully operational throughout our works and of course, will be busy with frequent ship movements. We will also be keeping a close eye on tidal conditions, that always add to the complexity of a project.
We will work flexibly to facilitate the port’s operations as they continue to serve their customers and passengers over the six months we are on site. This will include creating a temporary mooring and berthing arrangements to allow two cruise vessels to berth over the Christmas period.
We are looking forward to our role in helping Portsmouth International Port achieve its ambition to welcome bigger cruise ships and ultimately 150,000 cruise passengers each year.
MARINE ENVIRONMENT CASE STUDY: North Portsea Island Flood Defences Phases 2 & 3
The second phase of the 10-year North Portsea Island Coastal Flood & Erosion Risk Management (CFERM) project was to improve the coastal defences at Milton Common and demolish Great Salterns Quay.
This involved constructing a 750m long erosion control rock revetment, a retaining wall and three flood bunds, varying in height from 0.2m to 1.5m.
The works were in close proximity to residential properties, took place in the tidal zone, and were located in a biodiverse environment, all of which had to be considered and accounted for in our approach. When we discovered a species of protected sea snail in the location, we decided to re-route our haul road so as not to damage their habitat.
Diverting and reusing waste materials
Once on site we realised that 80% of the original seawall was still in remarkably good condition. Rather than demolish it and rebuild as had been anticipated, we were able to use the existing structure and raise the height to meet the required flood protection level. This saved £50,000 and enabled what would otherwise have been waste materials to be reused.
During the demolition of Great Salterns Quay we recovered significant quantities of chalk. This was spread across the site so that it could dry, before being compacted and reused to create the new flood bunds. These were then covered with topsoil and planted up.
Construction work is intrusive by nature so we do all we can to be considerate of our communities. Communicating clearly and listening to feedback are fundamental to our approach.
Creating understanding between us and local people is central to our aim. We build on work begun in the consultation stage, to develop relationships and communicate frequently to keep communities up to date.
Throughout our work at Portsea, we have shared drone footage captured by our Civil Aviation Authority qualified operator, to update stakeholders on important stages of the construction via the Eastern Solent Coastal Partnership’s website.
The People’s Memorial is a tribute to the serving men and women of the British Armed Forces built on the shoreline of Langstone Harbour. It is a special place for the community and particularly to its creator, Willie Goldfinch, as it’s also where his doves roost. We provided safe access so that Willie could tend to them throughout the works. We also placed surplus rock at its base to improve future protection and refurbished a number of nearby benches.
Phase three of the North Portsea Island coastal defences is a three year project to provide protection to 1.85 km of coastline at Tipner Lake. The area has environmental designations including SPA, RAMSAR, Important Bird Area, SSSI, Designated Shellfish Waters and Bass Nursery Area.
We have constructed a 4m high, reinforced concrete seawall including large areas of encasement and sheet pile installation along the entire frontage of Tipner Lake over a three year period, to provide a continuous defence and protection against a 1:500 year coastal flood event.
Throughout we have liaised with Horsea Lane Allotment Association as to gain access we had to create a working strip through the allotments. They have been supremely patient and we were pleased to recently fully reinstate the area and return the affected allotments to them.
Abutting onto Hilsea Lido, we have also provided support for this community asset undertaking minor works including rendering a wall, creating an artificial turf seating terrace, and installing new perimeter fencing.