Marine Diesel Repower Shops, Shipyards & Commercial Vessel Operators
For Marine Diesel Repower Shops, Shipyards & Commercial Vessel Operators
A repower is a geometry problem before it's a mechanical one. The new engine has a different footprint, different shaft centerline height, and different accessory positions than what came out. Every bed, coupling, exhaust run, and service connection has to be redesigned to the actual hull — not a drawing that was never accurate to begin with.
We scan the engine room with the existing engine in place — capturing shaft centerline, hull structure, coupling geometry, exhaust routing, and the full service envelope — before the old engine is pulled. The new package is fitted digitally. Problems get resolved on a laptop, not at the dock with the vessel out of service. Carry-in cases, battery-powered, operational in your engine room in 20 minutes. We travel to your yard.
Service Listings
Engine Room Envelope Scan — Repower Fit Study
Full engine room geometry captured with the existing engine in place — hull structure, stringer positions, overhead clearance, bilge profile, and all service access geometry. The new engine package is dropped into this geometry digitally and fitted before the yard work begins. Interference with overhead structure, conflicts with existing plumbing runs, and access problems for the new service points are all identified before the old engine is unbolted. Common for single- and twin-screw repowers on commercial fishing vessels, crew boats, towboats, and working yachts where yard time is a direct cost.
From $1,800
Est. — contact for quote
Engine Bed & Foundation Geometry Scan
Existing engine bed stringers, floor frame positions, and hull bottom profile scanned so replacement bed plates and foundation structure can be designed and pre-fabricated to the actual hull. The fabricator receives real hull geometry — not a nominal drawing — and can pre-build the new beds off the vessel. When the vessel comes back into the yard, the new beds go in without the fitting and grinding that comes from working off measurements taken by hand in the bilge. Used on commercial vessels where original builder documentation no longer exists and on older hulls where decades of previous work have altered the original bed geometry.
From $1,400
Est. — contact for quote
Shaft Centerline & Stern Tube Geometry Scan
Existing shaft angle, centerline height, and stern tube position captured relative to the hull — the reference geometry every other repower dimension works from. Shaft angle determines engine mounting height. Centerline position at the coupling face determines coupling selection and new engine position. Stern tube geometry determines whether the existing shaft can be retained or needs replacement. All of it captured in a single session before the repower begins, so the engine and shaft arrangement is engineered to the actual vessel — not estimated from a drawing that may be 30 years old.
From $1,200
Est. — contact for quote
Coupling Face & Gearbox Output Geometry Scan
Shaft coupling face position and gearbox output flange geometry captured for new engine alignment planning and coupling selection. When a new engine and gearbox combination doesn't match the existing shaft coupling geometry exactly — and it almost never does — the coupling and intermediate shaft arrangement has to be designed to bridge the difference. Knowing the exact position of the existing coupling face before the new equipment is ordered prevents expensive surprises during installation.
From $950
Est. — contact for quote
Exhaust Routing & Wet Exhaust System Geometry Scan
Existing exhaust manifold outlet position, waterlock location, exhaust hose runs, and thru-hull fitting geometry captured relative to the new engine mounting position. Wet exhaust systems on repowered vessels are a consistent problem: the new engine's exhaust outlet is in a different position and at a different height than the old one, and the existing waterlock, hose runs, and thru-hull can't always be reused in their current locations. Scanning the existing system and the new engine position together lets the exhaust system be designed before yard work begins — not improvised during installation.
From $950
Est. — contact for quote
Engine Room As-Built — Full Service System Scan
Complete engine room as-built geometry including fuel supply and return lines, raw water and freshwater cooling plumbing, exhaust system, electrical runs, battery locations, and service access geometry. Used for full repower engineering packages, insurance documentation, vessel sale or transfer, and engine room modification planning. Deliverable is a complete as-built model the engineer, naval architect, or marine surveyor can work from.
From $2,200
Est. — contact for quote
Hull Appendage & Underwater Geometry Scan
Propeller shaft, strut, rudder post, sea chest, keel cooler, and bow thruster housing geometry captured on hauled-out and drydocked vessels. Used for replacement part fabrication when OEM components are discontinued, damage documentation for insurance and repair estimation, and geometry verification when the installed configuration no longer matches the original drawings. Common on older commercial vessels where decades of previous repairs have altered the underwater geometry from its original documented state.
From $1,400
Est. — contact for quote
We Travel to Your Yard
We come to your boatyard, marine railway, dry dock, or dock facility. Carry-in cases, battery-powered — no shore power required, no special setup in the engine room. Within 50 miles of Nashville is included in all base prices. Tennessee and Cumberland river yards are regional. All pricing is estimated — contact us with your vessel type, engine count, and yard location.
| Within 50 miles of Nashville 37206 | Included |
| 51–150 miles | +$180 |
| 151–300 miles | +$295 |
| 300+ miles | Quoted individually |
| National travel | Contact for quote |
When Repower Shops & Yards Call Us
Scenario — Commercial fishing vessel repower
A 45-foot commercial vessel is getting a new Volvo IPS package. The beds need to be redesigned and the shaft angle changes. The original builder is gone.
No original builder documentation exists for the hull. The new drive package requires a different bed configuration and a shaft angle that doesn't match the existing stern tube. We scan the engine room with the existing engine in place — hull structure, current shaft line, stern tube angle, bilge profile — and give the marine fabricator real hull geometry for the new bed design. The new beds are pre-fabricated off the vessel. The yard hauls the boat, the old engine comes out, the new beds go in on day one, and the installation proceeds without the measurement-and-grind cycle that adds days to every repower without documentation.
Scenario — Twin-screw towboat repower
A twin-screw inland towboat is being repowered with new Detroit Diesel engines. Both shaft lines need to be captured along with the relationship between them.
A twin-screw vessel where both engine positions, both shaft angles, and the lateral distance between shaft centerlines all have to be captured together — because both new engines have to be positioned relative to each other and to the hull simultaneously. We scan both shaft lines in a single session and deliver a coordinate dataset that gives the marine engineer everything needed to position both new engines correctly relative to each other, relative to the hull, and relative to the existing shaft lines — before either old engine is removed.
Scenario — Exhaust system mismatch
A repower is underway and the new engine's exhaust outlet is 8 inches higher and 14 inches forward of the old one. The existing waterlock can't be reused in place.
A classic repower problem discovered mid-installation. The new engine's exhaust manifold outlet position doesn't match the existing wet exhaust system — wrong height, wrong fore-aft position, wrong clearance to the existing waterlock. A scan before the old engine was removed would have identified this and the exhaust system would have been designed and built before yard work began. For the next repower, we scan both the existing exhaust system and the new engine's installation position and the exhaust system design happens at the drafting table, not in the bilge.
Scenario — Haul-out, strut replacement
A strut is damaged and needs replacement. The OEM strut is discontinued. A custom replacement needs to match the shaft angle and hull geometry exactly.
A damaged shaft strut on a commercial vessel — the original manufacturer no longer supports the model and no replacement is available. A custom strut needs to be fabricated that matches the shaft centerline angle and the hull surface geometry at the mounting location. We scan the strut, the surrounding hull, and the shaft line while the vessel is hauled, and give the fabricator the geometry needed to build a replacement that goes on correctly — correct shaft angle, correct hull-surface contact geometry, correct bolt pattern.
Scenario — Engine room documentation for sale
A commercial vessel is being sold. The buyer's surveyor wants a complete as-built record of the engine room before the survey.
A buyer's due diligence requirement — a complete as-built record of the engine room: engine positions, shaft lines, all service plumbing, electrical runs, and access geometry. The marine surveyor works from the scan data alongside the physical inspection, and the buyer receives a permanent geometric record of the vessel's mechanical configuration at the time of sale. For the seller, it pre-empts post-sale disputes about undisclosed modifications or undocumented configuration changes.
Scenario — Bow thruster housing replacement
A bow thruster housing is corroded beyond repair on a 1980s vessel. No OEM drawings exist. A custom replacement tube needs to match the existing hull cutout.
A corroded bow thruster housing that needs full replacement — but the tunnel geometry, the hull cutout dimensions, and the tube angle relative to the vessel centerline have never been formally documented. The OEM for the original installation is out of business. We scan the existing tunnel and surrounding hull structure while the vessel is hauled and deliver the geometry to the fabricator. The new thruster tube is built to match the actual cutout — correct tunnel angle, correct diameter taper, correct flange geometry.
Questions from Repower Shops & Yards
Why scan with the existing engine still in place?
The existing engine defines the current shaft line, coupling geometry, and all service connections relative to the hull. Once it comes out, that reference is gone — and rebuilding it from hand measurements taken in a dirty bilge is slow, error-prone, and often incomplete. Scanning before removal captures the full spatial relationship: shaft centerline, coupling face position, exhaust outlet height, sea water inlet locations, and the hull structure around all of it. The new engine package is fitted into that geometry digitally, and every interference, mismatch, and design decision is resolved before yard work begins rather than during it.
Can you capture shaft alignment geometry for a new engine installation?
Yes. We scan the existing shaft at the coupling face, the stern tube exit geometry, and the shaft angle relative to the keel. These are the three references that determine how the new engine must be positioned to align with the existing shaft line. If the shaft is being replaced as part of the repower, we capture the stern tube geometry and the design shaft angle so the new shaft and engine can be positioned correctly from the start rather than aligned after installation through multiple adjustment cycles.
Can you work in a confined engine room on an older commercial vessel?
Yes. The HandyScan Black Elite is handheld, requires no tripod or fixed setup, and operates from battery. It works in the confined, irregular spaces of commercial vessel engine rooms — around existing machinery, in the bilge, under overhead structure. We've scanned in spaces where a conventional measurement crew would struggle to get a tape measure to the right place. Setup is 20 minutes anywhere the vessel is accessible.
What does the marine fabricator actually receive?
Hull geometry in STEP or OBJ format for bed and foundation design, shaft line geometry as a dimensioned reference drawing, coupling face position as a measured coordinate, and exhaust system geometry as a dimensional layout — all referenced to a common coordinate system the engineer can work from. Format requirements vary by shop and engineering team; we discuss what's needed during scope review and deliver what the fabricator can actually use rather than a standard package.
Do you scan on hauled-out vessels for underwater geometry?
Yes. Hauled-out and drydocked vessels are the best opportunity to capture underwater geometry — shafts, struts, rudders, sea chests, keel coolers, and thruster housings are all accessible. For replacement part fabrication on discontinued components, damage documentation, or geometry verification when the installed configuration no longer matches the original drawings, we scan whatever is accessible while the vessel is out of the water.
Can you handle a twin-screw vessel where both shaft lines need to be captured together?
Yes. Twin-screw repowers require both shaft lines, both stern tube geometries, the lateral distance between shaft centerlines, and the relationship of each shaft line to the hull structure — all in the same coordinate system. We capture both in a single session and deliver a unified geometry dataset the engineer uses to position both new engines correctly relative to each other and to the hull simultaneously, before either old engine is removed.
Ready to discuss your repower or yard project?
Tell us the vessel type, engine count, and what you need geometry for. We'll respond within one business day.