A Damen Quality Inspector’s 8-Point Checklist for Stan Tug Delivery

Who This Checklist Is For

If you’re taking delivery of a new tug or workboat—maybe a Damen Stan Tug, maybe another yard’s product—this checklist is for you. I work in quality at Damen Shipyards, and every vessel that leaves our yard crosses my desk first. That’s roughly 120 newbuilds and repair handovers per year. In 2024, I rejected about 11% of first delivery attempts because of spec deviations, missing paperwork, or—this is the big one—things the buyer assumed were included but weren’t written into the contract.

Honestly, the number of handover disputes I’ve seen over the last decade is way higher than it should be. I went back and forth about publishing this, because it’s basically our internal process. But the owners we deal with deserve to see it before they sign, not after. The checklist below is the one I walk with on every handover. There are eight steps. Most take under an hour. One of them usually finds something worth fixing.

Step 1: Write Down What “Complete” Means

Sounds basic, but most tug purchase orders define what the vessel will do, not what the delivery includes. “Turnkey” means different things to a buyer and a production manager. On a $4M Stan Tug, the gap between those definitions can be a $200,000 change order.

Before you sign, get a line-item scope: main engine, gearbox, winch, fire system, navigation electronics, spare parts, first fills, even the tooling. If a line says “suitable for anchor handling,” ask “suitable” for which anchor size and what wire diameter. We had a client who assumed the delivery included a spare propeller because the contract mentioned “spare running gear.” It didn’t. Adding that one item was an $18,000 change order in week three.

I’ve learned to ask “what’s not included” before “what’s the price.” The vendor who lists exclusions upfront—even if the total looks higher—usually costs less in the end.

Step 2: Compare the Class Certificate to the Physical Vessel

Get the class certificate (ABS, DNV, Lloyd’s, whichever) and walk the vessel line by line. I caught a 3-ton deck crane certified on paper but physically a 2.5-ton unit on our last project. The supplier said it was “within industry standard.” It wasn’t. Normal tolerance for installed vs certified is zero when a safety certificate is involved. We rejected it, they replaced it at their cost, and now every contract includes a certificate-matching clause.

Check dimensions, displacement, bollard pull, and the actual maker plates on engines and winches. A maker plate that doesn’t match the purchase order is a red flag, not a paperwork issue. The surveyor’s job is to catch this before the vessel is officially delivered, because after that the cost of the fix lands on the operator.

Step 3: The “Hawk vs Tail” Inspection

My old superintendent called this the hawk vs tail check. It sounds odd, but it means the two spots everybody forgets: the hawse (the bow area around the anchor chain and line lead) and the tailshaft (the propeller shaft at the stern).

On the hawse: check the wear plates, chain pipe alignment, and chafe protection. A misaligned chain pipe turns a calm anchorage into a wire-fraying ordeal. On the tailshaft: check the seal for weepage, the rope guard, and the shaft locking clearance. If I remember correctly, we had a vessel in 2023 with a tailshaft seal that looked dry at the factory but started weeping a week after delivery. It should’ve been caught at handover. The replacement cost wasn’t huge—about $4,000—but it pulled the vessel out of service for five days during a charter.

Step 4: Verify Bollard Pull With a Test, Not a Curve

Everything I’d read about tug acceptance said the spec sheet bollard pull is gospel. In practice, we’ve seen a 12% difference between the paper number and a measured pull test on identical vessel types. One of those differences led to a contract penalty and a redesigned propeller nozzle. So if the spec says 27 tonnes, ask to see a test result from a properly calibrated load cell. If the vessel isn’t finished yet, book a bollard pull trial before handover and make it part of the acceptance criteria.

The test is straightforward: secure the tug to a shore bollard or a barge, run the engine up to full rated power, and read the measured pull on a calibrated load cell for a solid five minutes. A few thousand dollars for the test beats a six-figure warranty dispute after delivery. If you’re buying a standard Damen Stan Tug, we can show you bollard pull data from sister vessels. That’s useful context, but it’s not the same as testing your hull with your prop.

Step 5: Check the “Invisible” Systems

This is the part that gets skipped because everything visible looks great. Check the winch drum capacity with the actual wire diameter you’ll use. Check the hydraulic oil cooler against the ambient conditions—we saw one project where the cooler was sized for 25°C water, but the vessel was heading to a tropical port. Check the towing hook release mechanism with the engine running, not just with hydraulic pressure. Check bilge alarms, battery condition, and the fuel polishing system.

On a Damen Stan Tug 1606, these systems are standardized, so there’s less variance. But “less variance” isn’t “no variance.” The auxiliary checklist is where I find the most warranty claims. A towing hook release that works when the engine is off can behave differently when the deck is vibrating and the winch is under load.

Step 6: Corrosion Protection: Anodes and Coating Thickness

A 30-minute check here saves a ton of money later. Use a dry-film thickness (DFT) gauge and measure the coating at the waterline, the rudder, and around the propeller. Anything below 250 microns at the waterline is a rework, not a touch-up. Check the anodes: are they the right alloy for the water you’ll operate in? Not all zinc is the same. At the turn of the millennium, anodes were a line item nobody cared about. Now they’re the first thing a charterer’s surveyor touches. We had a batch of anodes fail prematurely in brackish water because they were specced for ocean water. It was a $22,000 fix and a six-day delay.

Step 7: Ask What’s NOT Included

Honestly, this is the most underrated question in marine procurement. Transport, sea fastening, commissioning engineer, crew travel, fuel for sea trial, delivery voyage pilotage, first-fill oils, customs clearance, spare parts beyond the mandatory extras—each one is reasonable as an exclusion. The problem is when they’re not stated.

I’ve seen a buyer budget $150,000 for “extras” on a tug that cost $3.8M, only to face a $180,000 bill for transport and commissioning alone. A transparent quote lists all exclusions at the bottom. We do that at Damen. If you’re dealing with a yard that doesn’t, ask why. And clarify what “commissioning” covers: a phone call with the engineer or three weeks onboard? Those are very different line items.

Step 8: Sea Trial With Your Own Load

The conventional wisdom is to do a sea trial at light draft with a few engineers onboard. My experience with 150+ sea trials suggests otherwise. Make the tug tow something at operating draft—a barge, a deadweight load, even a frozen propeller. That’s when the cooling system, propeller efficiency, and rudder authority show their real behavior. A 27-ton bollard pull at light draft means nothing if the engine is 10% hotter than the rating at full load.

The numbers said the winch met spec on paper. My gut said something was off during the trial. Turns out the winch could pull the load, but its brake couldn’t hold it at the rated load after 20 minutes of heat soak. My gut flagged it; the data came later. Always keep both. We had to re-run one trial because the barge we used was too small to give a stable reading—so make sure your test load matches the tug’s actual working conditions.

What Most Owners Get Wrong

Three common mistakes I see again and again:

• Trusting verbal assurances. If it’s not in the contract, it doesn’t exist. Write down the exclusions, the standards, the tolerance limits, and the test conditions.
• Skipping the certificate-vs-vessel check. A class certificate is a legal document. The vessel is physical reality. They need to match.
• Doing a “nice weather” sea trial. You’re not buying the tug for a nice weather day.

I presented a version of this checklist at the first congress on marine warranty surveying I ever attended, back in 2019. The room was quiet until one owner stood up and said, “nobody ever tells us to ask what’s not included.” That’s the whole point.

Use the checklist as-is or adapt it to your operation. At least, that’s been my experience with Stan Tugs and workboats in the energy and mining space. If you’re taking delivery of a vessel in the next six months, walk through these eight steps. It’ll save you more than the purchase order’s contingency.