Projects
Completed works, ongoing projects and concepts, from 1999 to today. Projects marked “Founder's project experience” are ones our founder worked on as part of another company's team, not under the Yan & Partners name.
Thin-layer green roofs with MDP
Thin-layer green roofs drained by MDP, collecting rainwater for reuse.
View project →
Island Eastern Corridor pile cap repair
Working platforms and access cages for repairing defective pile caps under the Island Eastern Corridor.
View project →
Lung Kwu Chau: uncovering a buried outfall diffuser at −22 mPD
A daily diving plan to find and clear a buried seabed diffuser near a busy fairway, 6–8 nautical miles from the typhoon shelter.
View project →
Kai Tak River: riverbed inspection, drain seals and diversion screens
Three years of diving work in the Kai Tak River for the Central Kowloon Route: a CCTV survey of the riverbed, steel seal plates for live drains, and underwater diversion screens around the new bridge platform.
View project →
Box culvert desilting, Hoi Fai Road to Olympian City
Diver-operated desilting of a flooded box culvert, with on-site settling and dewatering so only dry spoil leaves the site.
View project →
Pui O sewage outfall: diffuser installation method
A nine-step method, prepared at tender stage, for installing a diffuser on the Pui O outfall inside a sheet-pile cofferdam built from a temporary jetty.
View project →
Third Runway: pile-cap cofferdam and watertight formwork
A temporary-works scheme for casting marine pile caps at the Third Runway: a sheet-pile cofferdam, a steel trestle and a 62-tonne watertight formwork lowered over each pile group.
View project →
Exhibition Station: sealing and reopening drains in a live culvert
Confined-space diving on the Shatin to Central Link at Exhibition Station: surveying a flooded box culvert, sealing branch drains from Ø900 to Ø2,100 mm, and later removing the temporary bulkheads.
View project →
To Kwa Wan – Kai Tak: steel walers for a tunnel cofferdam
Steel waler and strut frames to brace the sheet-pile walls of a tunnel cofferdam, drawn in 3D for fabrication.
View project →
Lamma Island cement plant jetty: pile wrapping and fenders
Removing and refitting the pile wrapping and fender frames along a dolphin jetty, completed in 16 days.
View project →
Avenue of Stars: removing old marine piles
Underwater cutting and removal of the old marine piles beneath the Avenue of Stars for its expansion.
View project →
Causeway Bay seawater pump house intake
Underwater inspection and construction at the seawater intake of a building's cooling-water pump house.
View project →
Tseung Kwan O: sheet-pile bulkhead and silt-curtain frame
A steel frame for driving a sheet-pile bulkhead and holding a silt curtain, plus a water-stop gate for the drain behind it.
View project →
Tai Po Water Treatment Works: pumping sand from a deep culvert
Divers working from a man-cage at the bottom of a 2 m caisson removed 50–70 m³ of sand from a water culvert with a 3-inch sand pump.
View project →
Stonecutters Island sewage culvert: stop-gate bulkhead
A diver-installed steel stop-gate built up in sections inside a live sewage culvert, after a CCTV and measurement survey.
View project →
Stanley: encasing a sewage outfall pipe on rock
A Ø450 mm outfall crossing a rocky foreshore was encased in concrete using steel formwork, sandbags and mortar bags.
View project →
Multipurpose Drain Pipe (MDP)
Our patented drainage and filtration pipe that resists clogging. Silver Award, HKMA/HKT Global Innovation Award 2024/25.
View project →
Tseung Kwan O submarine cable: relocating the beach manhole
Moving the beach manhole where an international submarine cable comes ashore, using precast units, underwater pipework and grout placed from a floating platform.
View project →
Lamma Power Station jetty: working platforms and lifting frames
Temporary working platforms hung from the jetty piles, a platform for the fender dolphins and a vertical lifting frame for repair works at the Lamma Power Station jetty.
View project →
Submarine gas main: free-span inspection and support
Underwater inspection of a section of submarine gas pipeline left spanning over a scoured seabed, and a plan to support it and fill the scour with aggregate.
View project →
Temporary works design
Access towers, floating rafts and platforms we design so crews can work safely over and in water.
View project →
Chung Hom Kok: landing a new submarine cable
The shore end of a new cable at Chung Hom Kok: a 3 m trench through armour rock, an HDPE duct set in concrete, and a sea earth jetted into the seabed.
View project →
Diving 40 m down a flooded caisson shaft
Confined-space diving inside a Ø2,000 mm steel caisson about 40 m below ground: clearing sediment and cutting out the reinforcement underwater.
View project →
Airport artificial island: removing an abandoned telephone cable
Divers searched for an old submarine telephone cable buried up to 5 m deep, uncovered it by airlift and recovered it by winch before reclamation.
View project →
North Point: removing old dolphins beside the Island Eastern Corridor
Old concrete dolphins on bored piles were lifted out by crane barge after divers cut each pile 500 mm below the seabed.
View project →
Wan Chai Reclamation Phase 1 & 3
Seawall blocks and caissons for Section C2 (2010); temporary diversion pipes, cooling-water outfall works, stop gates and grouting for Section C3 (2016–2017).
View project →
Cross-harbour water main, West Kowloon to Sai Ying Pun: the landing
Underwater temporary works where a new cross-harbour water main comes ashore: cofferdam bracing to −15.7 mPD, pile cutting below the seabed, and a dry welding caisson at −17 mPD.
View project →
Xiamen–Kinmen fibre cable: burial to 3 m
Two diver teams trenched either side of a 32 mm submarine fibre cable so it lowered itself to 3 m below the seabed, checked every 10 m.
View project →
Seawater pump houses: installing trash screens
Divers set 11–16 m wide screen frames against the seawall at three seawater pump houses, drilling and welding underwater to close every gap.
View project →
Sai Ying Pun box culvert: bulkhead, joint sealing and grouting
A six-step method to isolate a seawall box culvert, clear it and seal its joints, with the bulkhead lowered at night by divers working inside.
View project →
Tuen Mun Area 38: finding and protecting outfall diffusers
Airlift searches for buried outfall diffuser heads, then extending and protecting the risers with rockfill and cement sandbags.
View project →
Shitai 158: patching a sunken cargo ship
Divers on mixed gas mapped and patched six breaches in a sunken cargo ship's hull, then a refloating plan was drawn for a grounded vessel.
View project →
Ninepin Group: lifting a fishing-vessel wreck from −31 m
Divers rigged slings around a sunken fishing vessel at −31 m so a derrick barge could right it and lift it.
View project →
Tong Fuk sea earth cables, Lantau
Laying and burying sea earth cables for the Tong Fuk international telecommunications station.
View project →
Tsuen Wan stormwater culverts: guide rails and stop gates
Removable steel stop gates on guide rails at the upstream and downstream ends of two stormwater culverts, installed by divers in about five days.
View project →
Black Point Power Station: clearing the cooling-water intake heads
Three dive teams located the offshore intake heads of Black Point Power Station, opened them, cleared the screens and airlifted silt from the pits.
View project →
Guangdong–Hainan 500 kV interconnector: protecting the submarine cables
Burying and protecting the 500 kV cables that link Hainan to the mainland grid: jetting them into the seabed at Xuwen, cutting through volcanic rock, and covering them with concrete slabs or grout bags at −35 m off Haikou.
View project →
AAG submarine cable: burying an in-service cable 5 m deep at −33 m
Divers airlifted a trench beneath a live Asia-America Gateway cable at −33 mPD, letting it sink 5 m into the seabed to −38 mPD.
View project →
SkyPier, Hong Kong International Airport: pontoon moorings
Setting typhoon sinkers of up to 68 tonnes and installing the elastic mooring system for the landing pontoons at the airport's ferry pier.
View project →
Kowloon Park swimming pool: refloating a sunken floor panel
A movable pool-floor panel sank to the bottom of the pool. Divers raised it evenly using inflatable hoses and floats.
View project →
Zhuhai: pulling a 550 m cable-duct bundle under a river
A 550 m bundle of seven HDPE ducts, ballasted with concrete weights, was pulled across a riverbed through steel sleeves in the levees and jetted in.
View project →
Peng Chau submarine pump station: condition survey
A diver survey of an offshore pump station built from four precast rings, gridded like a clock face so every defect could be located.
View project →
Cheung Chau–Lantau water main: finding a leaking joint
A diver inspection of the flanged joint between the steel and fibreglass sections of a submarine water main at −11 PD.
View project →
Discovery Bay shipyard slipway repair
Underwater repair of worn lifting-platform rails and a seabed depth survey for desilting at the Discovery Bay shipyard.
View project →
Castle Peak Power Station: sealing cooling-water culverts
Five years of diving work inside the cooling-water culverts of Castle Peak Power Station: sealing leaking joints with stainless plates, clearing intake screens and repairing a joint on the seabed within a 24-hour shutdown.
View project →
Stanley Pier reconstruction
Underwater welding, pile works and floating steel formwork for rebuilding a pier in open water, planned over 190 working days.
View project →
Ocean Terminal, Tsim Sha Tsui: seawall survey and repair
An underwater survey of the blockwork seawall from the Star Ferry to the China Ferry section, and repairs to voids and displaced blocks under the car park and pump houses.
View project →
Caltex Tsing Yi Terminal: twenty years of jetty maintenance
Recurring work at an oil terminal: inspection scaffolds for the pier piles, new rubber fenders, seawall grout bags and a full mooring-buoy package.
View project →
Guishan Island, Zhuhai: a blockwork unloading jetty
Design of a gravity jetty built from precast concrete blocks, stacked in eight courses from −12 to +7.5 PD on a graded rock foundation.
View project →
Our own cable and pipe burial machines
Design drawings for a jet sled that buries submarine cables up to 3.5 m deep and a trencher for 700 mm pipelines.
View project →
Quarry Bay sunken vessel: survey and salvage
Underwater survey of a sunken barge, then cutting it into three sections of 91, 119 and 180 tonnes to lift it out.
View project →
Tseung Kwan O: raising a sunken hopper barge
A step-by-step salvage plan for a sunken split-hopper barge, lifted with a derrick barge and moved to shallow water.
View project →
Fleming Road culvert: floating in a seal plate
A culvert survey every 40 m and a method for floating a 500 kg seal plate into a flooded culvert and fitting it by hand.
View project →
Tseung Kwan O – Lam Tin Tunnel: concreting formwork platforms
Suspended formwork platforms for placing concrete around marine piles on the tunnel project.
View project →
Improved underwater welding handle
Our handle design is now the standard across Hong Kong's commercial diving industry.
View project →Stanley Pier reconstruction
Underwater welding, pile works and floating steel formwork for rebuilding a pier in open water, planned over 190 working days.
Kai Tak River: riverbed inspection, drain seals and diversion screens
Three years of diving work in the Kai Tak River for the Central Kowloon Route: a CCTV survey of the riverbed, steel seal plates for live drains, and underwater diversion screens around the new bridge platform.
Avenue of Stars: removing old marine piles
Underwater cutting and removal of the old marine piles beneath the Avenue of Stars for its expansion.
Multipurpose Drain Pipe (MDP)
Our patented drainage and filtration pipe that resists clogging. Silver Award, HKMA/HKT Global Innovation Award 2024/25.
Wan Chai Reclamation Phase 1 & 3
Seawall blocks and caissons for Section C2 (2010); temporary diversion pipes, cooling-water outfall works, stop gates and grouting for Section C3 (2016–2017).
Causeway Bay seawater pump house intake
Underwater inspection and construction at the seawater intake of a building's cooling-water pump house.
Island Eastern Corridor pile cap repair
Working platforms and access cages for repairing defective pile caps under the Island Eastern Corridor.
Box culvert desilting, Hoi Fai Road to Olympian City
Diver-operated desilting of a flooded box culvert, with on-site settling and dewatering so only dry spoil leaves the site.
Tong Fuk sea earth cables, Lantau
Laying and burying sea earth cables for the Tong Fuk international telecommunications station.
Pui O sewage outfall: diffuser installation method
A nine-step method, prepared at tender stage, for installing a diffuser on the Pui O outfall inside a sheet-pile cofferdam built from a temporary jetty.
Tseung Kwan O submarine cable: relocating the beach manhole
Moving the beach manhole where an international submarine cable comes ashore, using precast units, underwater pipework and grout placed from a floating platform.
Lamma Power Station jetty: working platforms and lifting frames
Temporary working platforms hung from the jetty piles, a platform for the fender dolphins and a vertical lifting frame for repair works at the Lamma Power Station jetty.
Submarine gas main: free-span inspection and support
Underwater inspection of a section of submarine gas pipeline left spanning over a scoured seabed, and a plan to support it and fill the scour with aggregate.
Quarry Bay sunken vessel: survey and salvage
Underwater survey of a sunken barge, then cutting it into three sections of 91, 119 and 180 tonnes to lift it out.
Tseung Kwan O: raising a sunken hopper barge
A step-by-step salvage plan for a sunken split-hopper barge, lifted with a derrick barge and moved to shallow water.
Discovery Bay shipyard slipway repair
Underwater repair of worn lifting-platform rails and a seabed depth survey for desilting at the Discovery Bay shipyard.
Exhibition Station: sealing and reopening drains in a live culvert
Confined-space diving on the Shatin to Central Link at Exhibition Station: surveying a flooded box culvert, sealing branch drains from Ø900 to Ø2,100 mm, and later removing the temporary bulkheads.
Fleming Road culvert: floating in a seal plate
A culvert survey every 40 m and a method for floating a 500 kg seal plate into a flooded culvert and fitting it by hand.
Stonecutters Island sewage culvert: stop-gate bulkhead
A diver-installed steel stop-gate built up in sections inside a live sewage culvert, after a CCTV and measurement survey.
Tai Po Water Treatment Works: pumping sand from a deep culvert
Divers working from a man-cage at the bottom of a 2 m caisson removed 50–70 m³ of sand from a water culvert with a 3-inch sand pump.
Tseung Kwan O – Lam Tin Tunnel: concreting formwork platforms
Suspended formwork platforms for placing concrete around marine piles on the tunnel project.
To Kwa Wan – Kai Tak: steel walers for a tunnel cofferdam
Steel waler and strut frames to brace the sheet-pile walls of a tunnel cofferdam, drawn in 3D for fabrication.
Tseung Kwan O: sheet-pile bulkhead and silt-curtain frame
A steel frame for driving a sheet-pile bulkhead and holding a silt curtain, plus a water-stop gate for the drain behind it.
Tsuen Wan stormwater culverts: guide rails and stop gates
Removable steel stop gates on guide rails at the upstream and downstream ends of two stormwater culverts, installed by divers in about five days.
Temporary works design
Access towers, floating rafts and platforms we design so crews can work safely over and in water.
Castle Peak Power Station: sealing cooling-water culverts
Five years of diving work inside the cooling-water culverts of Castle Peak Power Station: sealing leaking joints with stainless plates, clearing intake screens and repairing a joint on the seabed within a 24-hour shutdown.
Black Point Power Station: clearing the cooling-water intake heads
Three dive teams located the offshore intake heads of Black Point Power Station, opened them, cleared the screens and airlifted silt from the pits.
Guangdong–Hainan 500 kV interconnector: protecting the submarine cables
Burying and protecting the 500 kV cables that link Hainan to the mainland grid: jetting them into the seabed at Xuwen, cutting through volcanic rock, and covering them with concrete slabs or grout bags at −35 m off Haikou.
Cross-harbour water main, West Kowloon to Sai Ying Pun: the landing
Underwater temporary works where a new cross-harbour water main comes ashore: cofferdam bracing to −15.7 mPD, pile cutting below the seabed, and a dry welding caisson at −17 mPD.
AAG submarine cable: burying an in-service cable 5 m deep at −33 m
Divers airlifted a trench beneath a live Asia-America Gateway cable at −33 mPD, letting it sink 5 m into the seabed to −38 mPD.
Improved underwater welding handle
Our handle design is now the standard across Hong Kong's commercial diving industry.
Xiamen–Kinmen fibre cable: burial to 3 m
Two diver teams trenched either side of a 32 mm submarine fibre cable so it lowered itself to 3 m below the seabed, checked every 10 m.
Chung Hom Kok: landing a new submarine cable
The shore end of a new cable at Chung Hom Kok: a 3 m trench through armour rock, an HDPE duct set in concrete, and a sea earth jetted into the seabed.
SkyPier, Hong Kong International Airport: pontoon moorings
Setting typhoon sinkers of up to 68 tonnes and installing the elastic mooring system for the landing pontoons at the airport's ferry pier.
Ocean Terminal, Tsim Sha Tsui: seawall survey and repair
An underwater survey of the blockwork seawall from the Star Ferry to the China Ferry section, and repairs to voids and displaced blocks under the car park and pump houses.
Thin-layer green roofs with MDP
Thin-layer green roofs drained by MDP, collecting rainwater for reuse.
Caltex Tsing Yi Terminal: twenty years of jetty maintenance
Recurring work at an oil terminal: inspection scaffolds for the pier piles, new rubber fenders, seawall grout bags and a full mooring-buoy package.
Guishan Island, Zhuhai: a blockwork unloading jetty
Design of a gravity jetty built from precast concrete blocks, stacked in eight courses from −12 to +7.5 PD on a graded rock foundation.
Seawater pump houses: installing trash screens
Divers set 11–16 m wide screen frames against the seawall at three seawater pump houses, drilling and welding underwater to close every gap.
Sai Ying Pun box culvert: bulkhead, joint sealing and grouting
A six-step method to isolate a seawall box culvert, clear it and seal its joints, with the bulkhead lowered at night by divers working inside.
Diving 40 m down a flooded caisson shaft
Confined-space diving inside a Ø2,000 mm steel caisson about 40 m below ground: clearing sediment and cutting out the reinforcement underwater.
Third Runway: pile-cap cofferdam and watertight formwork
A temporary-works scheme for casting marine pile caps at the Third Runway: a sheet-pile cofferdam, a steel trestle and a 62-tonne watertight formwork lowered over each pile group.
Lung Kwu Chau: uncovering a buried outfall diffuser at −22 mPD
A daily diving plan to find and clear a buried seabed diffuser near a busy fairway, 6–8 nautical miles from the typhoon shelter.
Tuen Mun Area 38: finding and protecting outfall diffusers
Airlift searches for buried outfall diffuser heads, then extending and protecting the risers with rockfill and cement sandbags.
Shitai 158: patching a sunken cargo ship
Divers on mixed gas mapped and patched six breaches in a sunken cargo ship's hull, then a refloating plan was drawn for a grounded vessel.
Ninepin Group: lifting a fishing-vessel wreck from −31 m
Divers rigged slings around a sunken fishing vessel at −31 m so a derrick barge could right it and lift it.
Kowloon Park swimming pool: refloating a sunken floor panel
A movable pool-floor panel sank to the bottom of the pool. Divers raised it evenly using inflatable hoses and floats.
Airport artificial island: removing an abandoned telephone cable
Divers searched for an old submarine telephone cable buried up to 5 m deep, uncovered it by airlift and recovered it by winch before reclamation.
Zhuhai: pulling a 550 m cable-duct bundle under a river
A 550 m bundle of seven HDPE ducts, ballasted with concrete weights, was pulled across a riverbed through steel sleeves in the levees and jetted in.
Peng Chau submarine pump station: condition survey
A diver survey of an offshore pump station built from four precast rings, gridded like a clock face so every defect could be located.
Lamma Island cement plant jetty: pile wrapping and fenders
Removing and refitting the pile wrapping and fender frames along a dolphin jetty, completed in 16 days.
North Point: removing old dolphins beside the Island Eastern Corridor
Old concrete dolphins on bored piles were lifted out by crane barge after divers cut each pile 500 mm below the seabed.
Stanley: encasing a sewage outfall pipe on rock
A Ø450 mm outfall crossing a rocky foreshore was encased in concrete using steel formwork, sandbags and mortar bags.
Cheung Chau–Lantau water main: finding a leaking joint
A diver inspection of the flanged joint between the steel and fibreglass sections of a submarine water main at −11 PD.
Our own cable and pipe burial machines
Design drawings for a jet sled that buries submarine cables up to 3.5 m deep and a trencher for 700 mm pipelines.