By: Bas van Dam

Espaņol Nederlands

Welcome to the preliminary homepage for the WESP.
The WESP is a large multi-purpose vehicle constructed to aid in the research of the Dutch coastal area. It can operate from the beach and drive into the sea upto waterdepths of 8 meters (app. 26 ft).

First some technical details to give an idea of the incredible size of the WESP!

Design physical features: Height of platform : 11 m ( 33 ft) Size of platform : 6 x 2,5 m (18 x 7.5 ft) Cabin on platform : 2,85 x 1,4 x 2,2 m ( 8.5 x 4.2 x 6.6 ft) Base: equilateral triangle : 9,9 x 9,9 x 9,9 m ( 30 x 30 x 30 ft) Between wheel centers: 11 m (33ft) Material WESP: Base triangle : Steel pipe 193,7 mm dia. x 8,8 mm ( 7.63" dia. x 0.35") Vertical legs : Steel pipe 193,7 mm dia. x 5,0 mm ( 7.63" dia. x 0.20") Cabin : Aluminum Net weight : 10.000 kg (22,000 lbs) Driving gear: 3 wheels; one of which steers: 1,6m dia. 0,8 m width (4.8 ft dia 2.4 ft width) 3 hydromotors with 20kNm torque capability. Diesel power unit. 77 kW (100 hp) with hydrogenerator suspended under the platform. Design operational features: Maximum waterlevel above groundlevel, excluding waves: 8 m (26 ft) Maximum waveheigth : 2 m (6 ft) Velocity: On the beach: 10 km/h ( 6 mph ) In water: 5 km/h ( 3 mph ) Maximum inclination in any direction: 30°

WESP on trial near Egmond aan Zee. Detail of cabin

A Davit crane with hydrolic winch is mounted on the rear-end of the platform capable of hoisting up to 1000kg (2200 lbs). It is intended for placing tripods etc.
In the cabin are the controls for driving the WESP, the rest of the cabin serves as accomodation for researchers and instruments. The WESP is also intended to haul a sledge or cart with instruments; it's operation beeing monitored from the cabin.

View looking in the cabin toward the front

Driver's viewport looking straight down at front wheel.

And now some of the applications of the WESP.

DGPS profiling

DGPS testing. (Dec. 1997)

Main task for the WESP is profiling; determining the elevation of the seabed and beach. On top of the WESP a Global Positioning System (GPS) antenna is mounted, which receives direct information from the GPS satellites orbiting the earth. A two way radio link relays this information towards the fixed fieldstation on the beach, that also has a GPS receiver. In this way the resolution of the measurements can be increased (Differential-GPS) and the operator on the WESP as well as the observers in the fieldstation are informed of the current position of the WESP.

A tilt and compass system is used to correct for the difference between the WESP GPS antenna position and the actual bottom some 15m below. The great advantage of using the WESP is the production of continuous tracks from the foot of the dunes up to waterdepths of about 8 meters. This eliminates the problem of combining ship conducted soundings and manual beach levelling.

During a survey the WESP is driven in straight cross-shore lines spaced about 50m apart. Every second a coordinate value from the DGPS is recorded. From the X-Y-Z coordinates a map can be plotted of the bottom elevation (Z) to the cross-shore displacement in the X-Y plane. The result from a single line can be viewed in the picture on the right.

DGPS bottom elevation profile, Egmond aan Zee

A typical survey covers dozens of cross-shore lines. From these multiple lines, a top view bathymetry map can be produced. As only the bottom elevation is know on discrete lines additional processing (interpolation) is required, to render the elevation contour lines as can be seen in the map on the right.

Bathymetry map from interpolated DGPS lines, Egmond aan Zee

Instrument deployment

Hoisting platform

Placing instruments

Towing the CRIS

In the spring of 1998 the WESP was upgraded with a hoisting platform that facilitated the handeling of heavy and large tripods. The tripods have been adapted in height, to enable the WESP to freely pass over the tripods. Instruments can be placed very quickly, which enables in-between inspections. This takes just one hour using the WESP, minimizing 'down-time'.

Lighter constructions can still easily be handeled by the Davit-crane as can be seen in the second picture. The CRIS is a small (by comparison) towed vehicle, which acts as an instrumentation platform to the WESP. In the study of sediment transports it is important that the instruments do not influence the currents and sediments under study.

The WESP itself is a large construction that causes a lot of turbulence in the water, therefore it is not possible to conduct the experiments with instruments on the WESP. CRIS measurements are conducted only on some days. Inbetween the CRIS can be decoupled, to free the WESP for other tasks.

Testing the WESP to the limit.

Imagine trying to find a parking space during office hours!

The WESP was constructed by order of the Ministry of Transport, Public Works and Watermanagement, Directorate-General of Public Works and Watermanagement, National Institute for Coastal and Marine Management/RIKZ (Homepage ) and engineered by Sigma Engineering.

The design was derived from the Coastal Research Amphibious Buggy (CRAB), constructed by the US Army Corps of Engineers. The people of the CERC field research facility at Duck, North Carolina are thanked for giving their kind permission to copy the design and for all the aid and cooperation in constructing this Dutch version of the CRAB.

• Rijksinstituut voor Kust en Zee (RIKZ) Homepage; WESP owner.
• Information on WESP DATASETS on NEONET.(Dutch)
• Magelas Belgium; WESP user.
• Scheutjes Systeemhydrauliek (Dutch) , the company that engineered the WESP hydraulic system.

• Coastal Research Amphibious Buggy (CRAB); the original where the WESP was derived from.

Back to the laboratory homepage.

HTML Created Feb 19th, 1997 by Bas van Dam Updated Sept 27th, 2001