Client: Kew Gardens, Surrey.
Type of works: installation of Olympic pool-sized composting facility, using the Alfabloc® walling system.
The Royal Botanic Gardens at Kew has a compost heap the size of an Olympic swimming pool. Making compost of the right consistency and nutritional value is vital for this 300 acre World Heritage Site, which attracts over one million visitors every year to see its world famous horticultural collection. A higher heap creates more heat, so rotting can happen very quickly. This in turn helps Kew achieve a quick turnaround and meet its objective of making compost from a combination of shredded cuttings, plant-pot waste and manure, in as little as six weeks. Poundfield Products, a UK-based company specialising in producing high-quality, concrete retaining-wall systems, has been a vital part of the solution.
Kew Gardens other premises at Wakehurst Place in West Sussex, already uses L-shaped blocks as a retaining wall. For Kew, staff were looking for a superior solution, one that could stand up better to their rugged demands. So when they came to construct the retaining wall to their compost heap, they turned to Poundfield Products' Alfabloc® retaining-wall system.
For Kew, there were a number of issues to consider, the main one being that the wall should be very robust and able to support the composting material up to a height of 2 or 3m. The compost is shifted around within the compound using front-loading excavators with large buckets. They had found that the L-shaped blocks in use elsewhere had not provided a complete solution. The foot needed to be outward-facing, to allow them to scrape the contents out easily without damage, but this meant that they were not suitable for separating bays as the toe side could not be used.
Horticultural Support Manager, David Barnes says: 'I worked together with Carol Belshaw, Building and Civil Engineering Manager, to come up with a solution. We found the Alfabloc® on Poundfields website and after investigating them, we decided to order more than 70 units earlier this year. Everything went very smoothly and our Alfabloc®s arrived over the course of three days, delivered where and when we wanted. Because of the logistics of delivering into the heart of the site, we had to transport them ourselves from the perimeter of the site to where they needed to be installed, close to the stable blocks.'
He adds, 'We chose Poundfields Alfabloc® because we wanted something that had a lot of flexibility. Its quite possible that we will want to unbolt them and move them around. We have been absolutely delighted from start to finish. Poundfields sales manager was very good and extremely supportive. She smoothed the way from start to finish and gave us an excellent after-sales service.'
Kew Gardens would consider purchasing more to solve similar problems on the strength of its experience with Poundfield Products Alfabloc®.
The Alfabloc® walling system is an A-shaped, freestanding storage unit that can be loaded from either side without the need for ground fixings. It is pre-cast and reinforced, and interlocks for extra strength. It was developed at Poundfields premises in Suffolk and is widely used at ports, farms, recycling sites and in many other industries.