Terrain Aeration

Terrain’s deep aeration in Yorkshire Sculpture Park

Situated near Wakefield, West Yorkshire, the Yorkshire Sculpture Park is an open-air gallery that showcases work by world-class British and international artists, including Yorkshire-born Henry Moore, Barbara Hepworth and Damien Hirst. The park has one of the largest open-air collection of Moore’s bronzes in Europe. Spread over 500-acres of 18^th century designed landscape of Bretton Hall, YSP opened in 1977 and was the first UK sculpture park based on temporary open-air exhibitions that were organized in London parks from the 1940s to 1970 by the Arts Council and London County Council.

Today, the ‘gallery without walls’ has an ever-changing exhibition programme and preparing to reopen after lockdown presented an opportunity for remedial work to be done. Following a site visit by hydrology consultants inspecting a waterlogged area, they brought in Terrain Aeration with their deep aeration treatment system. The area in question was an important part of the Lower Park and a popular area for visitors and curators. It suffers from compaction due to footfall and the weight of sculptures, resulting in the build-up of standing water.

 “It is unusual for the area to be cleared,” says Mark Chesman, Head of Estates and Parks at YSP, “but the sculptures in that area were removed for conservation work, and we seized the opportunity as part of a wider project. In all, it took two-and-a-half days and they treated 4,000 square metres of land.”

Terrain Aeration’s Terralift hammers a hollow probe one metre into the soil using a JCB road breaker gun. At depth, the ground is usually so compacted it needs the hammer to break through. Compressed air is then released to a maximum of 20Bar (280psi) to fracture and fissure the soil and the process is repeated in two-metre spacings, to ensure the fissures interlink. On the end of the air blast, dried seaweed is injected which sticks to the fissure walls, expanding and contracting with moisture content in the soil and keeping the area ‘breathing.’ The 1.5-inch probe holes created by the Terralift machine are backfilled with aggregate to provide a semi-permanent aeration/ventilation shaft, helping to keep the whole aeration process working. The park’s groundkeepers then overseeded the area to finish.

We tend to take trees for granted, in our parks, public spaces and estates but they are often subjected to stress as a result of several factors, such as nutrient shortage, surface compaction due to foot traffic, and waterlogging where water drains off hard surfaces. Yorkshire Sculpture Park features lime trees, beech and Atlas cedar amongst others and these were given Terrain Aeration treatment as well. Breaking up the soil around the roots, and beyond, means excess water will drain away from the roots to help stop anaerobic conditions and rotting of the root system. “We’re confident with what’s been done,” says Mark, “and will be looking at further areas to be treated, probably in the autumn.”

Terrain Aeration 01449 673783 www.terrainaeration.co.uk

Image: Sophie Ryder, Sitting, 2007. Courtesy the artist and Yorkshire Sculpture Park.

Photo © Jonty Wilde, courtesy Yorkshire Sculpture Park. View this photo

Image: Sophie Ryder, Sitting, 2007. Courtesy the artist and Yorkshire Sculpture Park.
Photo © Jonty Wilde, courtesy Yorkshire Sculpture Park.

2021 News from Terrain Aeration

David and Lynda would like to wish everyone a safe 2021.

This is our update on our position during lockdown and to say as soon as the B&B’s start opening we will get on with our backlog of work that requires overnight stays. We are pleased to say we are able to resume day work within travelling distances and these are starting up.
We like everyone else have been caught out with the Covid-19 pandemic and its mutations.
We have been unable to work away from base as this requires us to night stop in Bed and Breakfast places, as well as needing somewhere to eat in the evenings. Travelodge are very proud and pleased that they are able to stay open to have beds available for the NHS staff but we feel that the extra risks involved sharing this sort of accommodation for some of our staff who are “shielding” vulnerable family members is not safe despite the efforts put in by the hotel staff to keep the virus at bay.

In November 2020 when lockdown was eased and infection rates were low, we took on more staff in order to be able to work our way through the backlog of work which has been accumulating. The new variant of the Coronavirus and the repeated lockdowns meant that even with extra capacity we could not treat any areas because of the lack of safe accommodation.

The staff are being kept upgrading our machinery for when it is safe for them to go out and work.
The extraordinary efforts to get those who are most vulnerable vaccinated will be a welcome relief, once our staff are able to get their jabs – unfortunately this could well be as late as September!

We have ear-marked our work on a map and will do the work in “batches” to save us running up and down the country doing a garden or sports field here and there. With the new staff, we can double up on our work and hopefully with totally rebuilt machinery, get the work done quickly. Once suitable accommodation is found, we will be able to use it as a base, so our staff are reduced in their exposure to the virus, which will unfortunately, still be around.

All safety precautions will be taken by our staff – there is no need to come into contact with our clients: phone calls and photos will suffice. We have all the PPE required – no chances will be taken.

On a new note of caution – with our machines working in gardens, more people are staying at home and on “Zoom”. We must remind them that our machines do make a great deal of noise and that they will be unable to hear any Zoom meetings.

We are on a pretty tight schedule and having to switch off the machine and stop work for the homeowner to use “Zoom” will have a knock on effect and delay our schedule – perhaps even making us stay over another night to get the work completed and delaying all other work for the rest of the week.

Rest assured that Terrain Aeration are not closing their doors but are simply staying safe.

There is no area of grass however revered and loved that is worth the life of a Terrain Aeration member of staff or one of their vulnerable family members.

We thank you for your patience and we will get around to treating your ground.

Great Field project for Terrain Aeration

Poundbury, the urban extension on the outskirts of Dorchester is well-known for reflecting the design principles of HRH The Prince of Wales, on whose land, the Duchy of Cornwall, it is built. The Great Field, at some 12 ha, is the largest area of green space in Poundbury and work began on it in 2014, with the building of sports pitches, outdoor gym equipment and a multi-use games area. One area which is developing especially well was sown around five years ago and is now a sea of Common Knapweed, with plentiful Ladies’ and Hedge Bedstraw, Quaking Grass, Bird’s-foot Trefoil and other meadow wildflowers.

During 2020, further significant work has been undertaken with the planting of over 400 trees and 26,000 shrubs and hedging plants. The charity People Need Nature has worked with the Duchy of Cornwall and local seed supplier, Heritage Seeds, to sow another wildflower meadow on the Great Field. Exceptionally wet conditions followed by unusually dry periods, led to compaction and waterlogging, resulting in a slow start for the meadow.  Improving the ground conditions to assist establishment of the trees, shrubs and hedging was identified as particularly important.

The services of specialists Terrain Aeration were called upon to relieve the compaction and panning on the top half of the field. They brought in their Terralift machines, which work on the principle of hammering a hollow probe one metre deep into the soil, using a JCB road breaker gun; the soil is compact at depth and requires the hammer to break through. At one metre depth, a hydraulic blast of compressed air is released at up to 20Bar (280psi). This fractures the soil, creating fissures. The process is repeated at two-metre intervals on a grid pattern with the fissures interlinking to create a system of aeration and drainage.  The Terralift is the only machine which uses such high pressure to enable the process to work. On the tail end of the blast, dried seaweed is injected and this sticks to the walls of the fissures, expanding and contracting with the moisture content in the soil. The probe holes are backfilled with aggregate to maintain the aeration process.

The new Great Field meadow sown with wildflower seed collected from existing meadows in Purbeck, should be flourishing within the next two years. The local sourcing helping to protect local populations of native wildflowers. As part of the usable green space area for the local community, the meadow will be cut in July, with the low-growing flowers, such as Red Clover and Bird’s-foot Trefoil, continuing to flower and provide nectar and pollen for insects.

IT'S OUR BIRTHDAY!
Celebrating 20 years as Terrain Aeration Services using
the Terralift machines.