A9 BaHo: exceptional lifting work Sarens Netherlands

During the widening and deepening of the A9, Sarens Nederland is providing all the specialist crane work. Of particular note is the lifting and transport of the two new bridge falls, or bridge decks, of the Schiphol Bridge. An assignment that Sarens can certainly add to its list of special achievements.

The construction consortium VeenIX is widening the A9 between the Holendrecht interchange and the Badhoevedorp interchange on behalf of Rijkswaterstaat. This includes the Schiphol Bridge, a movable bridge with two decks (falls), one per main roadway. Both bridge decks have been renewed. "What makes it special is that both new bridge decks are anything but straightforward in terms of shape and design," says Jaap Zwarthoed, depot manager Sarens Netherlands location Amsterdam. "In addition to the bridge decks, we internally transported and installed two 'specials' or precast concrete cover plates at the site of the bascule basement. These have the shape of a pie slice. Because of this different shape and a weight of around 100 tons, the center of gravity was difficult to determine which made the transport and placement anything but easy."

Smart lifting solutions

The work for the Schiphol Bridge is right up Sarens Netherlands' alley, a specialist in crane rental, heavy lifting and special transport. What they are particularly strong at is coming up with smart solutions for complex lifting and transport jobs. Their rental service provides various lifting and transport equipment for a variety of projects. They also have their own engineering department that prepares complex projects in consultation with the executing parties.

Three-point elevator

The lifting and transport work of the two new bridge falls of the Schiphol Bridge was carried out by Sarens on behalf of Hollandia Infra. The latter is responsible for the execution design, fabrication and assembly of the two new bridge sections and the new drives. Transporting the bridge falls was the first hurdle to be taken. Hollandia Infra built the bridge traps on site in Krimpen aan de IJssel. From there, they had to be transported by water to the Schiphol Bridge. "Here we definitely had to think out of the box," said Marco IJdo, senior project manager at Sarens Netherlands. "Because the center of gravity of the bridge traps was only known theoretically, a lot of execution models were made for verification to place the bridge traps. Normally you have a four-point hoist, now we had a three-point hoist for hoisting in the bridge cases with our cranes. Our engineering department calculated and prepared a special lifting and transportation plan with specific lifting equipment to lift the bridge falls separately as safely as possible."

Huge transport structure over water

Sarens developed an ingenious transport arrangement: a structure of several metal towers and braces on a pontoon to transport the bridge falls. To give an idea of the forces being worked with: the north halyard was 436 tons in weight, the south halyard 370 tons. Both bridge falls were about 30 by 35 meters. IJdo: "It is a unique project. For the Department of Public Works, it is also one of the largest bridge falls in the Netherlands."

Hoisting with four cranes

At the Schiphol Bridge, each bridge halyard was then lifted with the necessary precision from the pontoon into the right place using four large cranes, including a 700-tonner, a 450-tonner and two 500-tonners. In the process, the individual bridge traps not only had to be lifted in height from the pontoon, but also brought in horizontally and placed subsequently. 

Nothing is too heavy

In addition to this exceptional transport and lifting work, Sarens is handling the lifting of the concrete girders of all structures on the A9 section for various suppliers, as well as the installation of the prefabricated columns and the large reinforcement baskets on which the girders will rest after the concrete is poured. They also supply the cranes for extending the anchors in the sunken construction pit near Amstelveen and hoisting pontoons in/out. "These are all specialized lifting operations for which we are in demand. Our motto is not for nothing: Nothing too heavy, nothing too high."