Port of Cromarty Firth

Our team was appointed by Cromarty Firth Port Authority Ltd, a busy port in northern Scotland servicing floating North Sea infrastructure, to conduct a marine ground investigation to characterize ground conditions ahead of the port's phase 5 development, including quayside extension and laydown area. The continued development of the port required information on the superficial soils and underlying bedrock to advise the design parameters of the proposed piled quay walls.

The scope of work included:

• 37 overwater boreholes by sonic/rotary drilling
• 11 cone penetration tests, 9 with sonic/rotary follow-on
• Marine Scotland testing for dredge disposal
• Works were completed off the Causeway Giant 1 (CG1) Combifloat C5 Modular Jack-up Barge
• Factual ground investigation reporting

Ocean Wind One

In summer 2022, team members from Seas Geosciences, including Gregg Drilling, conducted a successful geotechnical survey that supported design of the landfall methods of the cables that will carry power from offshore wind turbines to the shoreline. Our work involved two primary services: cone penetration testing, which profiles the soil up to 20 feet below the seabed, and companion drilling and sampling, which removes soil cores for analysis in a lab.

Seas Geosciences used an innovative approach to working in ultra-shallow water for this project. Teams deployed an amphibious carrier - equipped with drilling and cone penetration testing gear - to go from land to water up to 15 feet deep. This vessel can smoothly transition from the surface to floating, which makes for efficient ground investigation in a beach situation like this one. Novel solutions like this enabled us to execute our part of the project within three weeks, safely and on time.

Scapa Deep Water Quay

The proposed development of Hatston Pier and deep-water quay at Scapa Flow in Scotland's Orkney Islands called for investigation of the superficial soils and bedrock geology to progress the design and construction. The project's remote location and high HSQE standards required a trusted network of sub-contractors and suppliers and careful planning from inception to delivery. Work was completed on time, despite challenging weather and logistics.

The scope of work included:

• 29 no. overwater boreholes by sonic drilling and Geobor S wireline coring
• 10 no. wash probes by sonic sampling methods
• 1 no. surface sediment sample by Van Veen grab sampler
• Environmental sampling of the soft sediments for Disposal at Sea analyses
• UXO Survey
• Overwater works were completed out off an C5 Combi-float Self Elevating Platform supplied by OCM
• Factual ground investigation reporting

Naver Bridge, Scottish Highlands

Our team investigated superficial soils geology to aid design and construction of a replacement bridge in this remote and challenging location. We overcame the difficulty of very dense gravels and cobble/boulders to depths of 50m bgl using our experience with sonic drilling techniques from other marine projects. By carrying a broad stock of drill bits, we were able to react to different rock types and ensure continued rock coring. Another significant challenge was the remote set up of the barge being constructed on a tidal river near an existing bridge in an area of limited space. Thanks to careful planning and a network of trusted subcontractors, the work was completed safely and ahead of schedule.

The scope of work included:

• 4 no. overwater boreholes by sonic boring and Geobor S wireline coring
• 5 no. boreholes by rotary drilling sampling methods
• 9 no. boreholes by sonic drilling sampling methods (land)
• 9 no. machine dug trial pits with infiltration tests in four pits
• 12 no. road pavement cores
• Indirect CBR tests at thirty-five locations
• Pebble survey and marine geophysical surveys within the River Naver
• Downhole televiewer surveys at three locations
• Overwater works were completed out of an C5 Combi-float Self Elevating Platform