Allelys Completes UK’s First Double Girder Frame Convoy

Allelys have executed the UK’s first-ever double girder frame convoy while delivering a
reactor and transformer to Ninfield. The reactor weighing 150t, and transformer weighing
195t, were transported on specialist girder frames with a total combined transport weight
of 667t gross travelling in tandem.

The cargo was delivered in three parts: from Stafford to Ellesmere Port, via sea, then
Shoreham Port to Ninfield.

The girder frame was built up in Stafford using a 55t mobile crane and the reactor,
measuring 10m (l) x 5m (w) and 5m (h), with a total transport length of 68m, was loaded
using an overhead crane into the girder frame. The same process was used on a different
day to load the transformer, measuring 9.75m (l) x 4m (w) and 5m (h), with a total transport
length of 67m.

The first stage of the road transportation was to Ellesmere Port, where one of the units
were transhipped onto a 10 axle SPMT using a 200t lift n lock system. The SPMTs,
carrying the transformer, and the girder frame, containing the reactor, were then loaded
onto the Terra Marique vessel. To decrease the ground loading pressure during the
manoeuvre, Allelys utilised load spreading mats and stools.

The next stage involved the sea transportation to Shoreham Port, where the reactor and
transformer were removed using ro-ro operations and were temporarily stored.

The final stage of transportation to Ninfield was the most challenging and saw two girder
frames used in convoy, one for each of the units, and configured with low set hangers for
the reactor. The two trailers reversed out of Shoreham Port in order to navigate a complex
turn onto the A259. Once through Brighton joining the A27, the team sought a solution
whereby they had to travel southbound on the northbound carriageway, before re-joining
the A27 by travelling Eastbound on the Westbound carriageway via contraflow, and finally
crossing over to the right direction by removing the central reservation. This was necessary
to avoid a structure at Patcham Viaduct on the A23.

The next challenge was crossing the River Ouse with such heavy cargo, by closing the A27
and constructing an overbridge to not exert load into the structure, with 27.5m bridging mats
that were positioned using a 500t and 300t crane lifting in tandem.

Finally it was necessary to navigate the tight streets and turns of Polegate Highstreet and
Bexhill in order to reach the final destination at Ninfield Substation.

Once on site, Allelys installed both units. The transformer was jacked up off the transport,
jacked down onto skates and then skidded 25m into position. Whilst the reactor was
transhipped to SPMT, lifted by Allelys 200te lift n lock system and positioned.

“This operation was extremely complex right from the start, involving several transportation
stages and requiring a lot of technical operations to negotiate obstacles and structures on
route. From convoying two girder frames, travelling contraflow, removing central
reservations and installing overbridges. There were many pinch points along the route that
the transport team effectively managed. The level of engineering and planning involved was
evident through the successful execution of the project,” said Zac Smout, Project Manager
at Allelys.

Source Allelys / Zero Two Digital Limited