Appendix A: Inspection and Review of Existing Infrastructure

Introduction

An inspection of existing facilities was undertaken to inform this overview statement of the relevant assets referred to in the brief and their present condition. This has aided the understanding of prospective problems, constraints and opportunities-from an engineering perspective, and has been fundamental to the optioneering exercise that has been undertaken as described at Chapter 6.

This overview statement describes the results from the review of marine infrastructure and road infrastructure, and presents outline costs associated with a range of infrastructure upgrades.

For marine infrastructure different upgrade options are considered together with a statement on the current state of the infrastructure and any alternate site considerations.

Marine infrastructure

Three types of slip service provision have been investigated and considered, as follows:

Basic upgrade: repair of cracked surfaces, reinstatement of missing concrete, remediating damaged joints, and allowing for a 30m long, 8m wide concrete slipway extending to Mean Low Water Springs following a natural beach gradient where this is close to 1:8 where in the case of any sites where no such slipway exists at present.
Upgrade to all states of the tide: as per basic upgrade plus extension and reprofiling of slipway to a 1:8 gradient, to achieve a 40m long slipway extending to 1m below Chart Datum and dredging a pocket at the toe of the slipway.
Upgrade to receive larger vessel: as per basic upgrade plus allowing for a 30m long, 8m or 12m wide slipway extending to Mean Low Water Springs following a natural beach gradient where this is close to 1:8. An 8m slipway would allow for use by landing class similar to the Gylen Lady as well as for vessels such as the MV Eigg and MV Raasay, whereas a 12m slipway would allow access for the larger CMAL Loch class vessels.

While the upgrade to all states of the tide and upgrade to receive larger vessels are both enhancements on the basic upgrade described above, both these upgrades could be provided together to provide a slipway that could receive a larger vessel at all states of the tide.

Kerrera Ferry slip

The existing slipway is in a reasonably serviceable condition although the loose stone breakwater is considered to be something of a hazard. To retain the structure in good serviceable condition the surface should be repaired, the breakwater rebuilt and the dumb barge (which forms part of the submerged breakwater) repositioned. There is an existing car park at Kerrera which anecdotal evidence suggests is adequate and no expansion would be proposed. The creation of a temporary livestock pen would be possible in the car park but it is understood that most livestock is herded onto the road and directly onto the vessel.

Port na Fhearna

This site is known to offer some natural shelter and could offer an alternative location for a new slipway in preference to upgrading the existing facilities. An advantage would be that the existing slipway service would be uninterrupted by construction work on the new site.

Scottish Sea farm slip

No information is available on the Scottish Sea Farm slipway's form of construction. However, it is understood that Scottish Sea Farm require access to the facility on demand and, consequently, would be unwilling to work around any scheduled service.

Oban Yachts slip

The existing Oban Yacht slip is extremely shallow, with substantial damage and deterioration in the upper areas and completely missing any concrete surfacing at the lower end. This is perfectly acceptable for yachts and dinghies but not satisfactory for the operation of a scheduled ferry service or freight service. For a basic upgrade the whole of the surface would require to be reconstructed with reinforced concrete and, even so, it would not be competent for most of the vessels which could operate a service due to its shallow gradient. For any further upgrade at this site the whole slipway would require to be demolished and reconstructed with a much steeper gradient. There is a large area for boat storage and parking at the marina and it is not considered necessary to create a new area for parking as this would be out with the slipway site.

North Pier (new pier on Kerrera)

This site benefits from the shelter of the pier and could offer an alternative location for a new slipway in preference to upgrading the existing facilities. An advantage would be that the existing slipway service would be uninterrupted by construction work on the new site although the slip could only be accessed if a purpose built road were constructed.

Gallanach slip

The existing slipway is in a reasonably serviceable condition although the loose stone breakwater is considered something of a hazard. There is an existing car park at Gallanach which anecdotal evidence suggests is regularly full and creates issues for ferry users and freight.

Lismore slip (Oban)

The slipway at Oban Ferry Terminal is slightly narrower than CMAL require for their larger landing craft vessels (Loch Class) but they are able to operate from there on an unrestricted basis using the MV Eigg/Raasay vessels. The Loch Class vessels can use the slipway but it is not their first preference - these vessels can also use the main linkspans but only at higher tides.

The geometry at Oban is such that it is not possible to widen the slipway at this location as it is locked at its present width by the structures either side of it. Consequently, the only option considered is its routine maintenance after which it will be competent for most vessels at all states of the tide.

Road infrastructure

Four forms of road construction have been considered, which comprise as follows:

Basic: clearance of surface organic material, sub-base layer with crushed stone/concrete surface where required and reinstatement of drainage.
Forestry standard: this standard is the level which can be constructed using locally won quarried rock (crushed) or imported stone, comprising: Clearance of surface organic material, excavation to competent foundation layer, sub-base layer with geotextile, crushed stone/concrete where required, type 1 aggregate upper layer for a 4.5m wide running surface, new drainage ditches either side of the road, reinstatement of drainage and passing places accommodated on wider stretches. Argyll and Bute Council have adopted forest grade tracks elsewhere in their area.
Non-sealed road: this standard takes the road up to near adoptable standard, but without a sealed bituminous surface. It is highly durable and requires only occasional maintenance, but its construction makes it suitable for most road vehicles subject to signage, bend radii and gradients. Make-up comprises: clearance of surface organic material, excavation to competent foundation layer or introduction of capping layer, sub-base layer with geotextile, crushed stone where required, type 1 aggregate layer or base course for a 4.5m wide running surface, new drainage ditches either side of the road, upgrade of existing drainage with culverts and new pipework, passing places at regular intervals and road signs.
Single track road: This standard takes the road up to an adoptable standard. It is highly durable and requires only occasional maintenance, but its construction makes it suitable for all but the largest road vehicles subject to signage, bend radii and gradients. Make-up comprises: clearance of surface organic material, excavation to competent foundation layer or introduction of capping layer, sub-base layer with geotextile, crushed stone where required, type 1 aggregate layer or base course for a 4.5m wide running surface, asphalt wearing course, new drainage ditches either side of the road with new pipework and road drainage where required, upgrade of existing drainage with new road standard culverts and new pipework, passing places at regular intervals and road signs.

There are three possible routes from the existing ferry terminal to link in with the existing road at Ardantyne, two of which pass close to Port ne Fhearna (which is a potential site for a new slipway as described above).

These routes are shown in the map at Appendix B.

Option 1: East route 1

The route is from the Kerrera Ferry slipway directly around the shore north through Port ne Fhearna and up over a small hill to join the road at Ardantyne. This option involves the removal of a large rock outcrop just northwest of the Kerrera Ferry slipway round to join the quad bike track south Port an Fhearna. From Port an Fhearna the road would follow the track up to Ardantyne .

The attraction of this route is that there is no requirement to scale the hill to Ballinmore. Furthermore, the excavation of the rock would generate a substantial proportion of quarried stone which would largely support the requirement for construction. However, the significant drawback of this route is that the removal of the rock outcrop would have a fairly significant visual impact leaving a scar clearly obvious from the mainland. There are also concerns in relation to the sightlines available in such close proximity to the existing road and whether this would only be alleviated by additional rock removal.

Previous studies have also commented on the concerns in relation to planning implications which have been considered to be sufficiently significant to have largely ruled this out.

Option 2: East route 2

This route follows the existing U57 from the Kerrera Ferry terminal to Ballinmore, where it turns north following the quad bike track down into Port an Fhearna and then up the track to Ardantyne.

Since it follows an established, if undeveloped, track the issues relate largely to upgrading the track and ensuring that adequate drainage is provided to allow existing water crossings to be maintained but also to ensure that groundwater run-off from the hills doesn't pond against the road.

This route will also have some visual impact but this is lesser compared to Option 1 as the road follows the existing track and will not be significantly apparent from the mainland.

Noted issues include the junction with the U57 which will have sightline issues for a junction on a reasonably steep incline. Signage may suffice to alleviate this issue.

Option 3: West coast route

An acceptable west coast route would commence at the Slaterich junction of the U57 (which will require to be upgraded) travelling east down the grassy track to the level ground and then joining the more established eastern track north over the culverted stream and into Ardantrive. The Slaterich junction is narrow and tight and will require careful consideration during any upgrade.

This route is a kilometre longer than the longest east coast route and is, consequently, more expensive. In addition, the existing track has several drainage issues which require to be addressed as well as a number of water crossings.

Ground conditions are generally more of an identified issue on this route, where there are various known soft spots which will require improvements, and any road improvement will need to address the impact of surface run-off ensuring that no impenetrable barriers are created.

However, the west coast is not visible from the mainland and so visual impact from this receptor is minimised. The impact from sea would be little more than at present where the track is hidden behind stone walls for much of its length.

Other roads on Kerrera

It is worth noting that there is no reason why the above options cannot be combined to achieve a single route around the hills on Kerrera. The developed concepts have been prepared to ensure that these can stand together whether the east coast option 1 or 2 is selected and linking into the western route.

A potential new site for a slipway has been identified opposite the North Pier close to Hutcheson's Monument. If this site were to become live then it would be necessary to link the existing road at the marina and Ardantrive to the new slipway.

Most of the new route would follow the present track to Hutcheson's Monument before turning east to the proposed slipway. The existing track is of a considerably higher standard generally than most of the other paths on the island. There are no noted water crossings and junction design is limited to joining with the existing road network. It is worth noting that upgrading will have implications in relation to power lines and drainage which are relatively simple but not trivial issues.

The existing road between the Kerrera Ferry slip and Gylen Park is generally in a serviceable condition, but an upgrade has been assessed and costed to improve the route to the same prospective standards as the other routes being considered on the island. The route runs north south and doesn't extend west to the tracks there although it could easily do so.

Estimates have been informed by measurement from maps and drawings. The road appears to be of a basic standard (with sound sub-base) in need of repair. There would be no significant planning issues with this upgrade although, as with most of the island, road improvements require to be undertaken sensitively to ensure that these do not exacerbate drainage issues or livestock issues.

Outline costs

Costs have been prepared based on the above options and conditions, utilising the inspection of the existing infrastructure and other sites considered.

**Table A1: Marine options**
Site	Basic Upgrade	Operate existing at all states of tide	To receive Larger Vessels 8m	To receive Larger Vessels 12m	8m vessel plus all states of tide	12m vessel plus all states of tide
Kerrera Ferry Slip	48k	265k	170k	215k	605k	660k
Port na Fhearna	n/a	n/a	488k	644k	1,287k	1,443k
Oban Marina	315k	1,050k	n/a	451k	1,050k	1,209k
North Pier	n/a	n/a	488k	644k	1,287k	1,443k
Gallanach Slipway	3k	175k-250k	n/a	185k	n/a	550k
Lismore Slip	15k	No further upgrade required	No further upgrade required	Operate on restricted basis	No further upgrade required	Operate on restricted bas

**Table A2: Road options**
Route	Length (m)	Basic	Forestry	Non-sealed	Single track
East 1 (shoreline)	1,670	590k	893k	1,513k	2,241k
East 2 (inland)	1,980	623k	1,003k	1,707k	2,544k
West coast	2,940	922k	1,566k	2,636k	3,944k
Full circuit	4,920	1,545k	2,568k	4,343k	6,487k
To north pier	1,470	265k	457k	966k	1,503k
Existing south road	3,440	661k	1,137k	2,341k	3,652k