Heavylift / Breakbulk
A detailed plan – now completed
Planning is at least half the battle when transporting heavylift and project cargo. This is particularly true of ambitious projects such as the shipment of eight tugs and one e-powerhouse on board a heavylift vessel. This project, undertaken by SAL Heavy Lift, proved that good planning really can pay dividends.
Sometimes it all comes down to size. The extraordinary loading capacity of the heavylift cargo vessel Svenja was one of the crucial factors when it came to the shipping of eight tugs from the Dutch firm Damen and one e-powerhouse, all on board SAL Heavy Lift’s freighter. The Svenja is a 183-type ship and is equipped with two cranes, each of which is capable of lifting up to 1,000 t. In addition it has the largest stowage space of all of the vessels in SAL’s fleet. It was nevertheless important to make optimum use of every available square metre on board for this ambitious effort.
The journey got underway in Vietnam, where SAL loaded six tugs aboard the Svenja in Haiphong, and another two in Da Nang. Each of these units weighed about 500 t and measured 28.6 x 14.4 x 15.8 m. The company placed six of the tugs above deck, and the remaining two below, thus ensuring that there was also room for the e-powerhouse. This was loaded in Batam (Indonesia), and was the first unit to be unloaded too, in Rio Grande (Brazil). It measured 22 x 28 x 23 m and weighed 1,263 t. The e-powerhouse is going to be used on a floating production, storage and offloading unit.
An innovative lifting concept to ensure no damage
As the tugs were already on board the vessel when the e-powerhouse was loaded, it was crucial that SAL developed an innovative lifting concept for this consignment, to ensure that the tugs did not get damaged whilst moving the additional cargo. The tugs were discharged in Lagos (Nigeria) and Rotterdam (Netherlands).
SAL Heavy Lift project engineer Sven Weide-Weddig describes the complex task as follows: «It was hugely advantageous that we were able to load all the tugs using just a single hook – despite each of the units weighing as much as 500 t.» According to Weide-Weddig this allowed SAL to act with the maximum of flexibility whilst rotating the units during the loading and unloading process. «Of course, the fact that we collaborated very closely with our client Damen also played an important role.» Weide-Weddig adds that the biggest challenge was distributing the weight of the e-powerhouse evenly across the load surface. Despite weighing 1,263 t the equipment had only four legs with a diameter of 1.2 m each on which its weight has to be distributed. In addition, its centre of gravity was very high, which resulted in very powerful forces acting on it. For this reason, SAL implemented a highly-detailed finite-element method – a calculation process used in engineering – in order to thoroughly investigate what would happen the moment the consignment was placed on the deck.
Once the engineers had worked out all of the aspects of the calculation required they designed and constructed a supporting transport frame. This ensured that the weight was placed on the strong areas previously identified on the deck; so ultimately, no additional weight distribution was required.