Case study regarding the scheme to realign St. Mary's Way in Sunderland, United Kingdom and populate it with healthy, long-lasting trees. Read more on this project here: http://www.deeproot.com/blog/blog-entries/transforming-the-character-of-st-marys-way-silva-cell-case-study

1. 7/2/2014
TRANSFORMING THE CHARACTER OF ST. MARY’S WAY:
STATE OF THE ART TECHNOLOGY GIVES LONG LIFE TO
STREET TREES ON NEW GREEN BOULEVARD
SUNDERLAND, UNITED KINGDOM

2. Sunderland urban design strategy, unveiled in 2008, aims to
revitalize city centre via the following:
1
Improving pedestrian accessibility
Creating a people-focused identity
Enhancing the public realm
Attracting new investors
Original Image: Stanley Howe; “From the Queen Vic Hotel roundabout” (Sunderland); License: CC BY SA 2.0; color altered here, this version licensed under CC BY SA 2.0

3. Central to these goals is the realignment of the ring road
connecting the riverfront to the city centre
2
“The new road is designed to
simplify traffic flow and improve the
connection between Vaux, the city
centre and the rest of Sunderland.
The boulevard design would
provide wider footways, a tree
planted central reservation and a
dedicated bus lane.
Realignment of St Mary’s Way
would also free up space to create
a high quality pedestrianised public
area, suitable for events or public
gatherings.”
Quote from city council spokesperson in Construction Enquirer; Images: Google Earth

4. Street trees form an integral part of these goals
The introduction of street trees can play a vital role
in establishing a distinctive, high quality
environment. They contribute to the appearance
and character of an area, filter dust and pollution,
and help make streets feel quieter and calmer. At
present there is limited street tree planting in the
central area.
3
From the Sunderland Central Area urban design strategy (2008), our emphasis in bold
Original Image: Stanley Howe; “From the Queen Vic Hotel roundabout” (Sunderland); License: CC BY SA 2.0; color altered here, this version licensed under CC BY SA 2.0

5. Trees are essential in reconfigurement of the ring road
There is significant opportunity to introduce further
street tree planting particularly where existing
streets and spaces are proposed to be
reconfigured. Tree planting should be a priority
along the ring road as part of its transformation
into a “Great Street.”
4
From the Sunderland Central Area urban design strategy (2008), our emphasis in bold
Original Image: Stanley Howe; “From the Queen Vic Hotel roundabout” (Sunderland); License: CC BY SA 2.0; color altered here, this version licensed under CC BY SA 2.0

6. “The creation of this new ‘green’
boulevard is seen as a crucial
element in meeting the aspirations
of potential investors and
encouraging development whilst
becoming a welcoming and
accessible city centre approach,
enhancing links to the port of
Sunderland and the future new
Business Quarter.”
James Gordon, Senior Landscape Architect
for Sunderland City Council
5Stills from 3D rendering video by Opsis: “St. Mary’s Way/Livingstone Road Sunderland Realignment”

7. Large specimen trees would help to attract businesses as much as pedestrians to the new
development and gateway.
But the City Council wanted not only to plant the trees near the roadways, but also to
ensure their prosperity for future generations, having a goal for the tree planting scheme
to be successful for at least fifty years. Silva Cells were specified for the project in
order to meet these needs.
6
The green boulevard will only succeed if the trees will last
Plan showing tree pit details for realignment of St. Mary’s Way, Sunderland City Council

8. 7
The Silva Cell is a modular
suspended pavement system that is
installed underground, providing a
void space for uncompacted soil
while also supporting the pavement
above it.
The system provides high soil
volumes to support large tree growth
and provide powerful on-site
stormwater management, and is
ideal for configuring hospitable
environments for trees in dense
urban sites.
Images by DeepRoot: Silva Cell schematics

9. “To assist us in delivering a new road
realignment through Sunderland City
Centre, DeepRoot played a key role in
transforming the character of the
highway network into a traditional tree
lined avenue, allowing us to plant large
specimen trees under footways and in
close proximity to the road.”
8Quote from James Gordon, Senior Landscape Architect for Sunderland City Council; Images by DeepRoot: Construction on St. Mary’s Way July 2013

10. The flexibility of the Silva Cell system
permitted Gordon and the design team
to work with the existing utilities and
other features of the site while still
providing adequate void space
beneath the road to give the trees
access to the nutrients required for a
long life. Gordon explains:
“In maximising the soil volume per tree
whist providing suitable load bearing
capacity, we are confident that we are
giving the trees the best possible
chance to thrive in this urban
environment. DeepRoot’s design
service allowed us to overcome
complex constraints such as existing
utilities, new surface water drainage
systems and dealing with trees on
such a large scale.”
9Images by DeepRoot: Silva Cell and Roots schematic; Silva Cell installation on St. Mary’s Way, July 2013. Contractors: Balfour Beatty

11. 10Images: Silva Cell installation on St. Mary’s Way, January 2013. Contractors: Balfour Beatty
Altogether, 1,772 (Silva Cell) frames and 866 decks were installed in a two layer system
along the new boulevard,
bringing 16.18 m3 (571.61 ft3) of soil volume to each of the 31 newly planted
trees.

12. 11
Through this ambitious creation of a new, tree-lined
pedestrian-friendly passageway, Sunderland’s vision
of a vibrant and prosperous city centre is one
tremendous step closer to realization.

13. 12
For more information on this project and using the
Silva Cell in the United Kingdom,
contact Stephen Chatwin-Grindey:
For more information on the Silva Cell, please visit:
steve@deeproot.com
www.deeproot.com