Biomass fuel presents a number of engineering challenges as it cannot be piped directly into buildings on demand like oil or gas and an efficient reserve of biomass fuel has to be stored and then delivered to the point of usage. The storage facility has to be well ventilated and dry as biomass is biodegradable and absorbs water if exposed. The material may also be required for loading onto a delivery vehicle for transportation entirely within the confines of the building.

HBPW has developed considerable expertise in the design, construction and detailing of buildings that require storage for bulk materials, and in particular biomass materials. The impact force of front loading shovels with the concrete walls of such buildings is normally very difficult to assess, but HBPW has a long track record in developing buildings that can withstand this.

Currently, a significant percentage of all carbon emissions in the UK comes from buildings, and it has now become a priority for both individuals and industry to use the world’s natural resources in a more economical and sustainable way.

When considering construction and the environment, an eco build should not be evaluated solely on its use of sustainable materials but also on its energy-efficiency over the long term. HBPW has been called upon to make an overall engineering assessment of the structural use of materials. The York Eco depot is a great example of how HBPW worked closely with a specialist architect to incorporate the detail necessary to give the depot ‘eco credibility’.

» Click here to see the York Eco depot case study

HBPW has worked on a considerable number of engineering projects with major developers, the Environment Agency and local water authorities, to design schemes to ‘attenuate’ the storm water flows from large developments in flood sensitive areas. HBPW has carried out flood risk assessments and carefully followed the design principle of the SUDS, Sustainable Urban Drainage Systems Hierarchy.

Major schemes undertaken by HBPW involving assessments for flood protection include the Radstone Technology development, Hancook Tyres and Barrett Steel.

Rainwater harvesting serves two purposes when assessing construction and the environment: it allows storm water to be channelled away from sewers or rivers, thereby easing the risk of flooding; and it enables this water to be stored and used for ‘grey’ purposes such as flushing the toilet and road cleaning. HBPW uses rainwater forecasts to determine the amount of rain that may fall on a site and then designs a rainwater harvesting scheme to capture it.

For commercial enterprises the uses can be many and varied. For example, at York Council Depot HBPW designed a rainwater harvesting scheme to wash refuse collection lorries. End users benefit from reduced mains water supply costs and recycling of a natural free product.

Precast Concrete Unit Manufacturer – Nottinghamshire: Considerable volumes of water are used for manufacturing precast concrete units for the construction industry, a large proportion being used for washing down and then discarded. Taking advantage of modernising their pre-stressing plant, a precast concrete manufacturer in the East Midlands installed a system to recycle water from their process, supplementing it with a rainwater harvesting system.

Many local authorities are adopting a co-ordinated approach to effective waste disposal where recycling, composting and waste transfer are able to be dealt with under the same roof.

HBPW has the necessary experience for the design of these sophisticated large-scale enclosed facilities and associated infrastructure. The Bidston Moss Recycling Facility is one of the largest of its kind in the UK. The site was a former incinerator which had been demolished and the ground conditions presented a severe challenge to HBPW designers who overcame the problems with a cost effective design. Building superstructures were designed to sustain the pressure of retained domestic refuse and the impact of front loading shovels.

The scheme is shortly to be extended to incorporate an in vessel composting facility and HBPW are closely involved with this development.

With the electricity industry under pressure to supply 10% of electricity from renewables by 2010 – the figure is currently 0.8% – wind power is likely to be a popular choice in Europe’s windiest country as it is clean and sustainable.

HBPW has worked on several major wind farms and has extended its considerable expertise in designing dynamic foundations for structures which ‘move’, as wind turbines do.

Ransom Moor Wind Farm, Cambridgeshire: HBPW’s engineering experience indicates that land-based wind farms are frequently situated on ground that provides challenges to the civil engineer in the design of the foundations.

The ground conditions at Ransom Moor Wind Farm were no exception comprising a thin stiff crust of clay over a great depth of very soft clay which had a consistency best described as ‘toothpaste’. HBPW assessed the dynamic response properties of the subsoils and designed piled foundations to support the turbines which extended to a height of 120 metres to the tip of the blades. A significant design consideration was also the capacity of the subsoils to support the weight of cranes erecting the windmills.