German heavy lift specialist Rolf Riedl GmbH and its Italian Partner ICW faced a technically complicated operation for client Linde Impianti Italia SpA: moving a modularised heater section from Leghorn in Italy to the Port of Immingham, UK, and onwards to Conoco's Humber Refinery. Especially challenging, writes GINO KOSTER, were the three radiant modules each weighing up to 248 tonnes, with centres of gravity as high as 16.5 m and a maximum allowable trailer width of 5.25 m.

The heater sections to be moved were designed and built by Linde in a small number of large and modularised components to allow easy and quick assembly at site, and to reduce additional manufacturing work at the refinery. The heater section was divided into various major parts. Three radiant modules, to be positioned next to each other at ground level, made up the base. All three modules were 24.9 m high but ranged in length between 14.9 and 16.8 m, in width from 6.5 to 8.1 m, and in weight between 211 and 248 tonnes. Two convection sections were on top, each measuring 20.6 x 4.8 x 3.7 m (lwh) and weighing 183 and 247 tonnes. Completing the heater, and sitting on the convection sections, was a stack in three parts and two take offs, taking the total finished height of 68 m. Although large in volume, these parts had a maximum weight of 26 tonnes. An additiional 90 tonnes of general cargo took the total project weight to 1307 tonnes.
A road and site survey by Rolf Riedl GmbH was undertaken as part of a preliminary overall survey to determine the most suitable means of transport. The survey established that the 24.9 m high radiant modules could not be moved from Linde's manufacturing location to the port area. As a result, a suitable location was found in the port for final assembly of the modules. From there the equipment had to be moved almost 2 km across the port area to reach a suitable roll-on quay. The survey revealed another complicating factor in that the available width between the supporting legs of the radiant modules was only 5.25 m. The weight, in combination with the high centre of gravity, required the use of an extra wide trailer for stability reasons, but did not allow for two standard 2.45 or 3 m wide trailers coupled side-by-side. A solution was found by using a 12-axle line Goldhofer modular trailer owned by Trans ADM in Belgium, allowing a six-line trailer to be split in half and coupled sideways to create a 1 1/2, 4.9 m wide trailer. Furthermore, the trailer would be self-propelled by integrating a six-line Goldhofer PST/ST, equipped with a power pack, in the trailer configuration.

Perfect planning
In close cooperation with Goldhofer's slient support engineering team, Riedl and Trans ADM drew up a method statement, including detailed drawings and stability calculations, of the trailer configurations with their loads. In addition, Goldhofer designed a set of beams for the radiant modules allowing for both proper load distribution on, and proper load securement to, the trailer deck. In addition, a complete frame was designed to carry the connection sections during both road transport and shipment including lashing eyes for sea fastening.

Like the radiant modules, the frame of the convection sections had supporting legs to enable the Goldhofer trailer to load and set down by using the 600 mm stroke to the hydraulic axles. This method meant that cranes were not needed.
Another part of the survey, dealing with the port facilities and the actual shipment of the cargo by sea, revealed other challenges. A suitable heavylift ship had to be found that met a number of criteria, notably: allowing for loading over a stern ramp; acommodating all the cargo in one shipment; offering a sufficient deck load per square metre and strong deck webbing to withstand the forces generated during shipment; being both technically able and permitted by the insurance company to sail with open hatch covers; and, last but not least, being available within budget during the required period of shipment.
Riedl's project team contracted MV Ostara, operated by Condock in Germany. The 4400 deadweight tonnage (dwat) vessel is allowed to sail with open hatch covers at reduced tonnage of 2300 dwat. Ostara has an open hold measuring 85 x 15 m and an 11 x 15 m stern ramp allowing axle loads up to 50 tonnes.
In close cooperation between Riedl, Condock and Linde, a detailed stowage and lashing plan was prepared to guarantee both the ship and its relatively high cargo against 6,3 m waves and a storm factor of 2.0400. A series of sea fastenings was designed and constructed, including side support beams, columns, distance tubes and stopper cleats.
During preparations the port authorities of Leghorn changed the proposed loading location three times. This resulted in adapting the roll-on plan, and finally required additional filling out of an area of about 7.5 x 6 m in front of the ramp. This was needed to enable the trailer to transfer from the quay on to the ramp and into the cargo hold by staying within the available axle stroke and without compromising the stability of the trailer. Although no road permits were required, Riedl had to apply for the authorisation of the Port Master to travel the 1850 m through the busy container facilities.
The thorough preparations paid off when the job was executed. The two convection sections, weighing 183 and 247 tonnes, were loaded first. This time Trans ADM used a second 12-line Goldhofer trailer in a conventional set-up with a hydraulic gooseneck. A four-axle MAN tractor provided the motive power. When the loads were secured on board the first radiant module weighing 241 tonnes and reaching almost 25 m in height was carefully manœvred over the ramp. It was loaded on the 1 1/2-wide Goldhofer which, with a capacity of 538 tonnes, gave a 2.2 safety factor.
While the sea fastening work was underway, other small cargo items were loaded on the first day. Despite deteriorating weather conditions the second and third radiant modules were loaded the next day. Loading the other small parts and carrying out the sea fastening required a third day, after which the Ostara set sail for the UK.
By sea, including crossing the Strait of Gibraltar and the English Channel, the journey took almost 14 days. Immediately after safely reaching Immingham, the discharge operation began. It took Riedl and Trans ADM less than 48 hours to roll off all cargo and to deliver it at an intermediate storage facility in the port area.