ST. EUSTATIUS–The stabilisation works on the cliff supporting Fort Oranje will be finalised this month. Since February 2019, 2,800 anchors, 7,400 square metres of canvas and just under 16,000 square metres of mesh have been placed to increase stability and stop erosion of the cliff for the next decades.
“I am very pleased that this challenging project was completed without any major delays. The workers of AcrobatX especially have achieved a great performance. In the blazing sun, hanging on ropes, they have placed 42 kilometres of anchors in the cliff,” stated Government Commissioner Marnix van Rij.
The French acrobats rappelling down the cliff have become an all-too-familiar sight for St. Eustatius over the last year. Their expertise in cliff stabilisation in France made them the ideal team for the job.
An important difference with their work here on Statia is that, in the homeland of AcrobatX, it is mainly about combating falling rocks. On Statia, it is important to stop erosion to prevent the historical landmark Fort Oranje from tumbling down.
The cliff on which the fort stands consists of various layers of volcanic stones and ashes pressed together. This type of cliff is very sensitive to erosion. Cavities have been created by groundwater seeping through the cliff, as well as by rain and wind.
Roaming goats play a major role in erosion too. They hide and sleep in the holes, but also create paths in the fine ash material of the cliff. Over time, cracks form along those paths, causing parts of the cliff to break off.
A lot of time was spent in adjusting the shape of the cliff to smooth out holes and cracks. After placing the metal tube anchors, which are up to 20 metres long, cement is injected to fix them into the cliff. To ensure that the anchor is properly secured, tests with a force of 250 tons are executed.
The multi-layered canvas bolted onto the wall is to protect from further erosion. The outer layer of mesh and canvas is intended to prevent possible movement of soil and to retain sand and seeds. Lastly, oleanders and beach morning glory are planted.
“I am relieved we have been able to safeguard our landmark Fort Oranje for the years to come. Special thanks to St. Eustatius National Park Foundation STENAPA, who will restore the natural face of the cliff by planting plants that come from our local Statia habitat,” said Deputy Government Commissioner Alida Francis.
Only a minor delay was suffered because in the final stage of the project the material had to be placed by hand instead of by helicopter. Due to the COVID-19 response measures, the pilot of the helicopter that installed the mesh during the earlier phases could not reach the island.
What remains now is to remove the sand, stones and sludge from the reservoir at the bottom of the cascade. This will be done by a local contractor.
Fort Oranje is expected to reopen at the end of May, and important events such as Statia Day may be held there once again in the not too distant future.
Bron: Daily Herald