HS2 and The Waterways - The construction solution using floating plant
Introduction - Ian Rothen (Founder of The Rothen Group)
The construction challenges posed by the High-speed rail (HS2) project include the crossing of the new line over 17 historic waterways at various locations across the canal network and three rivers. In addition, the enabling works will see the canal towpaths utilised to lay the high voltage cables. As a result of the proposed HS2 route, the only way to reach some sites and to start the construction phases of the project will be to utilise the waterways.
For HS2 contractors, this poses a set of specific challenges: replacing the high voltage cables along a towpath with weight restrictions, and other rules, to safeguard the various historic or protected sites from deterioration; navigating shallow, narrow, height restricted and awkward access sites to transport and take away building materials; and how lifting/construction equipment will be operated and stored.
For the last 200 years the waterways have been part of the UK's travel infrastructure and the good news is that with the right marine plant equipment and expertise, the UK’s canals and waterways can be used very effectively as a means for enabling and constructing the HS2 rail network. Without the right proficiency in the field however, the risks for contractors outsourcing works is particularly acute. Breaking regulations may impose substantial fines or other penalties and cause significant
delays to works. The implications of negative press should problems occur with a high-profile project like HS2 must also not be underestimated.
It is in everyone’s interests to protect the waterways and use considerate construction practices to complete the HS2 works, and in-practice this means calling in specialists to undertake relevant works in order to manage the posed challenges and subsequent risks.
To discuss any of the solutions mentioned in this article, or for more marine, civil and environmental engineering queries, please don’t hesitate to get in touch.
Enabling works - How do you work on a towpath?
To prepare for the works to start, understanding and complying with towpath rules and regulations is required. Key considerations, include:
Towpaths were not originally designed to bear weight in excess of a horse (one tonne max), so when constructing along the canals the use of heavy lifting machinery, like cranes and diggers, cannot always be performed from the towpath. It isn’t always possible to store or leave construction materials on a towpath
either, if the weight of building products and/or debris from construction are too heavy. The towpath is also used by pedestrians, so it is often a requirement to keep access open.
How do you get plant and materials to site with no land access?
When working with towpath weight restrictions or when land access isn’t available, floating plant can be positioned in the water to get equipment and materials to site safely. When combined with a grab barge (same principal as a grab lorry), which come in various sizes with different attachments to carry materials and offload independently, floating plant is ideal. Not only will floating plant provide a s table platform for plant equipment to hold materials, as well as complete all aspects of construction from, but by using floating plant there is also no risk of damaging the surrounding area either. A grab barge or digger pontoon can then work from the water to dig trenches, take away materials and transport new materials in - whether that be stone, cables, or lifting cable drums into position.
If only some land access is available, what then?
Where towpath weight limits allow, a micro digger can be lifted onto the towpath to carryout works. This can either be carried on a grab barge or crane pontoon to site ready for lifting off.
About floating plant
Floating plant can be designed in various different sizes and drafts (depths) to ensure that even shallow waters can be navigated safely. Depending on the width of the canal or waterway, a narrow or wide-beam solution will be recommended. Typically, in the Midlands narrower canal routes must be accommodated for, and in the South wide-beam canals are more common.
Canals in particular are often sloped at the sides and heavily silted against the bank, and therefore shallower at the edges, which is why floating plant needs to be designed so that construction equipment can get as close as possible to the side of the bank.
If a shallow drafted option is required then a mini digger pontoon with a pusher tug and hopper is recommended. The pontoon can be fitted with a crane and also carry a range of diggers from 2.5 – 8 tonnes in weight, depending upon whether they are being used on a narrow or wide-beam canal.
The pusher tugs literally push the floating skips, called hoppers, to/from work sites to be loaded from land or water-based plant. Typically, a narrow-beam hopper can carry up to 20 tonnes, the same carrying capacity as an eight-wheel lorry. A wide-beam hopper can carry up to 30 tonnes, the same as an arctic lorry.
Phase 1 & 2 - Land Restrictions
Depending on the severity of land restrictions, one of two options is usually recommended.
Site Access restrictions
With limited access, equipment and construction materials can be transported via the canal/river and offloaded at the site. The Rothen Group’s floating excavator pontoons, for example, float to site and then lower ramps onto the bank to track the digger/other plant off.
No land access
If no land access is available, as a result of either towpath weight restrictions not
allowing an excavator to be placed on the land, or due to the works needing to take place between two bridges for instance, then solutions exist to enable excavation works to happen off the pontoon itself.
Phase 1 & 2 - Working over waterways
It is likely that construction will need to happen over the waterways - for instance if a bridge needs to be demolished, widened, or inspected before works take place. When working over the waterways, a crash deck or floating pontoon can be used to create a stable working platform in order to place scaffolding, or if demolition is required this is also a way of protecting debris from falling into the waterway.
Civil engineering and construction work on the canals, rivers and water ways are different to the challenges faced on land and as a result include specific safety rules and regulations.
All equipment must meet safety standards, including the Boat Safety Certification, Stability Calculations for crane boats/pontoons and Lifting Operations and Lifting Equipment (LOLER) regulations.
Works carried out must also be completed by specialists who are qualified and trained to operate all boats and machinery safely. The core qualifications include, Construction Site Competency Scheme (CSCS), RYA Helmsman, Water Safety
Training, Site Managers Safety Training Scheme etc. Failure to to prove suitability of all boats, equipment and personnel on-site could result in fines and delay project completion.
Case Study: Cabling works along towpaths
In the winter of 2013, The Rothen Group worked with Western Power Distribution and
Morgan Sindall to replace and remove existing cables with new higher voltage cables, within canal towpaths in Birmingham.
Based very close to the city centre in a busy industrial and built-up area with few access sites, the first challenge was to find a solution to get the plant and equipment to the site. To further complicate the situation, the site was located within a flight of canal locks meaning that boating ‘traffic’ was high in the area.
To complete the job, The Rothen Group’s 70ft grab barge was used to load materials onto it before floating it to the construction site. Once at the site, all of the materials were off-loaded, and then the trenches for the cable dug.
For speed and efficiency, a shallow drafted tug and hopper solution pushed the floating hopper skips to and from the work sites to take away debris with ease, even in low waters.
To care for operatives completing the works and to also keep equipment safe from
potential t heft, floating welfare facilities along with secure floating plant storage for
equipment were both provided.
Ian Rothen, Founder of The Rothen Group, said: “Our knowledge of the canal network,
combined with the specialist boats and equipment we have designed to make
construction in awkward access sites and shallow water environments possible meant that the entire project was completed on time, in five months.”
Ian, continued: “Because of the minimal site access, the grab barge made life easier for everyone involved as materials could be brought to/from site with no trouble. It also meant that access could be kept open for pedestrians to walk along the towpath.”
How long does mobilisation usually take?
24-hours is the usual time taken, due to the design of the equipment being movable by Hiab lorry.
Will works disrupt pleasure boaters and how will this be managed?
Not normally. If boats are designed to allow other boating traffic to be able to pass, as is the case with The Rothen Group’s extensive fleet, then usually a banksman is employed to communicate what is going on to boaters and to help manage the public. Occasionally, construction works can involve lowering of water levels or lock gate works and therefore a ‘stoppage’ would be put in place in advance.
How environmentally-friendly is a marine hire solution?
A boat will typically use three litres of diesel per hour, while a lorry will usually use around 20 litres per hour. The Rothen Group’s fleet is marine approved to lessen the impact on the environment and protect the waterways.
The Rothen Group Capabilities
Over 70 boats
All excavators LOLER certified
Over 20 years' experience in marine, civil and environmental engineering
Trained operators for complete service solutions, or full training offered
Full project management capability
Ecological and environmental advisor
Storage and welfare pods also available for hire
The HS2 line creation is a momentous construction challenge that will make its mark on the history of UK rail and have a lasting impact on the travel infrastructure in Britain. All eyes are on the construction of the new line and as a result, contractors
cannot afford to accept anything less than excellence when it comes to construction on the canals, rivers and waterways during Phase 1 and Phase 2 of HS2.
Contractors must show that they have taken all reasonable precautions to complete works safely, efficiently and in line with regulation. Only through working with responsible marine, civil and environmental engineering businesses with a proven track-record of working on the waterways can this be achieved.
About the Author
Ian Rothen, founder of The Rothen Group – a national independent civil engineering and maintenance business servicing UK Waterways - has lived and worked Britain’s canals, rivers and lakes for the last 18 years. Having been born into a family of work
boat enthusiasts, Ian was exposed to the marine and plant hire industry early on, and started learning the family business at the
young age of nine.
Ian purchased his first work boat, a traditional ex-canal carrying boat, at the age of 15. The work boat, which is still in use thanks to being refurbished in 2017 to include one of The Rothen Group’s specialist cranes, was the start of a lifelong passion
and The Rothen Group today boasts over 70 work boats.
Now, Ian has developed the business, which was founded in 2012 under the trading name Ian Rothen Ltd, and rebranded into a national operation, The Rothen Group in 2015, servicing clients ranging from the Canal and River Trust and major contractors
This success can be attributed in part to the wide range of services The Rothen Group offers, and the unique problem-solving engineering behind the marine boat and plant equipment designed by Ian.