high level inlet works refurbishment with DFMA in mind,
collaborative working with the supply chain to drive innovation
by Chris Palmer
steel tank being lowered into position - Courtesy of North
STW is located to the north of the town of Retford,
Nottinghamshire. It serves a population of approximately 26,000.
The project was to address capital maintenance works which
includes the replacement/refurbishment of expired life items and
the addressing of operational risks. The inlet works screens
were capturing approximately 15% rags which was creating a high
impact on the treatment process and creating high operator
involvement on a daily basis with high OPEX cost. Adopting the
Design for Manufacture and Assembly (DfMA) approach the project
team delivered the solution minimising operational and process
impact during the construction phase.
An innovative DfMA
approach to the refurbishment of the inlet works was taken to
reduce the operational and process impact of the scheme during
the construction phase.
A stainless steel tank
and frame was designed and manufactured which would house the
new inlet screens. The whole assembly would be delivered to
site, pre-assembled and be lowered into position within the
inlet structure. High level scaffolding was designed and erected
to enable temporary pipework to be installed to control and
bypass the sewage flow during the construction phase. This
eliminated the need for high risk issues associated with
Collaborative working and
a factory thinking approach enabled safe but fast construction
on site, delivering the project ahead of a very tight programme
and minimising the risk to the sewage treatment process.
Early supplier engagement
was key to the success of the project. The NMCNomenca project
delivery team worked closely with the supply chain to ensure the
correct solution was obtained. Designs were created and reviewed
in a collaborative manner to ensure the innovation potential was
construction methods, the refurbishment of the high level inlet
works would involve heavy civil engineering techniques and
lengthy construction programme. By innovating with the
pre-manufacture frame, this was greatly reduced and health and
safety risk greatly decreased due to the factory thinking,
construction methods were not used, the site’s operational
carbon footprint was significantly reduced. The pre-assembled
frame was lowered into place with bypass walls etc.
pre-fabricated within the channels. Usual methods would mean raw
materials such as timber for formwork and concrete would have
The steel frame and inlet
screens were transported to site in one visit which greatly
reduced the CO2 emissions associated with multiple material
deliveries during traditional methods.
Retford inlet works pre-start - Courtesy of North
Engagement of the supply
chain and the client was maintained throughout the project. The
project team held collaborative planning sessions with
stakeholders to ensure focus at strategic hold points within the
NMCN held consultation
meetings with Severn Trent Water Wholesale Operations (End User)
throughout the project and incorporated their feedback into the
final design ensuring operational safety and full compliance
with the CDM Regulations.
Consideration to safety
was at the forefront of the project. The final solution was
designed with safety in mind. The construction programme was
reduced by two weeks by constructing in this way. Traditional
construction methods would have involved increased risks to the
Working at height.
Exposure to COSHH.
Project management and
A collaborative approach
was given to the entire project from initial proposals to hand
over to the client. Collaborative planning sessions were held
with the supply chain and client to build up the project
timeline. These key dates were then fed into the main
construction programme which ensured greater visibility of the
critical path to all involved.
Early procurement of the
inlet screens to the supplier with design acceptance agreed
ensured the usual manufacture period was within programme.
A manufacture programme
was issued to NMCN from the supplier showing key dates. The
dates were used for regular programme updates either via
conference call or at the suppliers’ premises.
During the construction
phase, weekly collaborative planning sessions were held in the
site cabin with all stakeholders to ensure the programme was not
only being met but challenged.
approach by the client, design and build contractor and
suppliers throughout the life of the project enabled the
innovative solution to be delivered within its tight timescales.
Installation complete at handover - Courtesy of North
Whole project impact
The project has made a
drastic improvement to the sewage treatment process at Retford
and significantly reduce STW operator time required on the site.
The client is more than
happy with the outcome, not only was the project innovative, it
was also the TOTEX solution.
and publishers would like to thank Chris Palmer, Project
Manager with NMCNomenca. for providing the above article for