The Press and Journal (Inverness, Highlands, and Islands)
Options to reconstruct road will cost millions
Councillors on Orkney will consider options for the reconstruction of the road on one of the Churchill Barriers when they meet next week.
Concerns about the surface of the road that runs along the top of the first Churchill Barrier have been doing the rounds for years.
It is believed that subsidence has caused warping of the road.
On Tuesday councillors on the development and infrastructure committee will consider a report that sets out six possible options for reconstructing the road
Most of these options include replacing the existing asphalt, but each of the options adds further steps at an increased cost. The options are: Replace the asphalt.
■ Replace the asphalt and include a reinforcing grid
■ As above and replace the existing sub-base material as well.
■ As above but also replace old tar-bound material.
■ Replace the asphalt including an asphalt reinforcing grid and replace the existing sub-base and old tar-bound material with a new sub-base wrapped in geotextile.
There’s also a sixth option, which is to do the minimum. This would mean only treating the worst of the cracking and failed patches or potholes in the road.
The report from council officers recommends exploring two of the options – the third and fourth.
The key difference between them is the replacement of the old tar-bound material.
However, the report notes that this is “difficult to justify”.
The projected costs for these options would be £1.275 million and £2.285m respectively.
It is thought option three would leave the barrier in a better state for 20 years at half the cost of option four.
But the risk with it is that the area in worst condition, where investigators found “excessive voiding”, might need additional maintenance during those two decades.
The fact that the council is finally considering these various options will come as a relief to many.
However, the plans are still at an early stage.
Councillors will not be making a decision on Tuesday over which option they want.
Rather, they will pick which ones should be looked at in greater detail before a final choice is made by the policy and resources committee.
These next steps will in themselves incur further costs.
The public have for years been raising concerns about the condition of the road on the first barrier – which links the Orkney Mainland to Lamb Holm.
In particular, those living on the isles linked to the Orkney Mainland by the four barriers have stressed the problems being seen with the road.
The council’s report refers to “defects in the form of longitudinal cracking and surface undulations” that have been appearing.
Since 2017, investigations have been undertaken by the local authority to identify the problem and see what could be done.
In 2019, a penetrating radar survey showed shadows that were thought to be voids deep within the barrier.
However, this was deemed inconclusive without further investigation being done.
Also in 2019, an advisory 40mph speed limit was introduced at the first barrier in an effort to keep motorists safe, particularly motorcyclists.
And in August last year, engineering consultant Mott MacDonald was appointed to provide support and advice to the council.
The firm reviewed all the existing data and dug “trial pits” at the barrier. It found that there are indeed defects caused by the construction and movement of the barrier.