Hey there, it’s Jake from [Your Company Name] Fender Davits – and before we dive in, let’s be real: installing fender davits on an oil tanker isn’t your weekend boat project. This is heavy-duty, high-stakes work, because these ships roll, yaw, and sway harder than any recreational vessel, and cutting corners here isn’t just bad – it’s dangerous for the crew, the fenders, and most importantly, the tanker itself. I’ve spent 12 years on the supply side of this game, working with shipyards and tanker crews across the Gulf, North Sea, and even a few stops in the Far East, and I’ve seen way too many botched installs that led to fender damage, davit failure, and even small accidents at sea. Today, I’m walking you through the exact process we train our clients on, straight from our in-house tech team – no fluff, no corporate jargon, just the stuff that actually works when you’re standing on a tanker’s deck with 500-pound davit parts. Fender Davits
First, let’s cut to the pre-install check – because skipping this is where 90% of problems start. You can’t just haul davits up and bolt them on without mapping your tanker’s specific layout, right? Tankers have super variable deck setups: some have flat midship decks, others have curved forecastle rails, and don’t even get me started on the difference between a Suezmax and a VLCC. First thing we do is confirm two non-negotiables: the deck steel thickness and the mounting point’s structural rating. A lot of guys assume the deck’s steel is uniform, but modern tankers have thicker plating around mooring bitts and thinner stuff near the rail for weight savings – drill into thin plating, and you’ll split the deck before you even lift the first davit arm. We always tell clients to run a magnetic thickness tester (they’re cheap, anyone can rent one) across every potential mounting spot. For our standard davits, we need a minimum of 16mm of steel at the base of the stanchion – anything less, and you either reinforce that spot with backing plates or upgrade to our heavy-duty thick-plate mount kit (we send these free with every order, FYI, no extra cost). Also, check the fender size you’re running – a common mistake is buying davits built for 2.5m diameter fenders when your tanker uses 3m ones. That leads to davit arms being too short, so when the fender compresses during berthing, it slips out of the cradle. We build our davits to be adjustable, but only up to a point – get that fender measurement right first, down to the millimeter. Oh, and weather check! I once saw a crew try to install in 30-knot crosswinds on a crude tanker, and they almost got the davit arm blown over the side. Wait for a lull, or schedule the install during calm seas – that’s non-negotiable.
Next, prepping the hardware and tools. I know, it sounds basic, but I’ve had a client show up with half the bolts wrong, or a drill that couldn’t penetrate tanker steel. Here’s the exact list we recommend, no surprises: M24 high-tensile bolts (grade 8.8 minimum, we include these with every davit set so you don’t have to source them), heavy-duty washers (locking and flat), backing plates (if your steel is under 16mm), a magnetic drill – not a handheld cordless, trust me, handheld drills will slip on tanker steel and mess up the holes – a torque wrench (digital ones are worth the $200, way more accurate than analog), a level (the small torpedo ones work, but a 1m spirit level for big straight edges is better), a chalk line, and safety gear obviously – harness, hard hat, non-slip boots, and a spotter on the ground at all times. Also, when you unbox the davits, lay them out on the deck and do a parts count. We pack every set with a stanchion, two arms, a cradle, pivot pins, adjustment brackets, and all hardware – if anything’s missing, call our tech team immediately, don’t try to improvise. Last year, a crew used a random pin from their toolbox because one was missing, and during a storm, the pin snapped, sending a 400lb fender overboard. Cost them $12k in replacement fender, plus a day of downtime – that’s avoidable.
Now, the actual install step-by-step, which is what you’re here for. First, mark your mounting holes. Use that chalk line to line up the stanchion – you want the davits spaced evenly along the fender line, usually 2m apart for standard fenders, but adjust if your fender lengths differ. The key here is getting the stanchion perfectly plumb, not tilted. If it’s leaning, when you lift the fender into place, the cradle will bind, and the davit will pull under stress. Once you mark the four hole positions for the stanchion base, double-check with the level – hold the level against the stanchion, adjust until the bubble is dead center. Then, clamp it temporarily with a couple of C-clamps (bring extra, they go missing fast on shipyards) while you drill. Drill each hole with the magnetic drill – go slow, don’t rush, because tanker steel can be hard, and a slow spin gives a cleaner hole that the bolts will grip better. Once the holes are drilled, clean out all the metal shavings with a wire brush – leave shavings in the holes, and the bolt won’t seat properly, leading to loose davits later.
If you needed backing plates (remember, steel under 16mm), now’s the time to fit those. We make these plates from the same high-tensile steel as the davits, so they match the stanchion’s mounting pattern – just set them over the holes, line them up with the stanchion base, and slide the bolts through. The backing plate spreads the load across a larger area of deck steel, so it doesn’t dent or crack when the fender slams into a dock. Now, thread the bolts through the stanchion and into the deck, hand-tight first, then use the torque wrench to get the exact torque rating. Wait, what’s that rating, you ask? For our standard davits, it’s 450 Nm for M24 bolts – don’t guess here. Too tight, and you’ll strip the bolt threads or crack the stanchion; too loose, and the davit will wiggle loose. We print the torque rating right on the stanchion base so you don’t have to look it up. Pro tip: do a “test torque” on the first bolt, then check the rest – sometimes the first one is a little off, so adjusting all to the same number is key.
Next up, the arm and cradle setup. This is where the adjustability comes in. Take the pivot arms and attach them to the stanchion using the pivot pins – make sure the pins are secured with the split pins we include, no exceptions. No split pin, and the arm will fall off at sea. Once the arms are in place, adjust their length to match your fender’s width. Most of our davits have sliding adjustment brackets, so you can extend or retract the arms by up to 30cm, which works for almost every standard tanker fender. Line the cradle (the part that holds the fender) to the two arms, tighten the adjustment bolts so the cradle is level – another check with the torpedo level here. Then, do a test lift: take a couple of crew members to lift a section of fender (or a dummy weight if you’re doing this before the fender arrives) and set it into the cradle. Rock it back and forth, see if the davit flexes too much – a little flex is normal, but if it wobbles more than an inch, you’re not tight enough. Go back and recheck all bolts, it’s easier to adjust now than after you’ve launched the fender.
Wait, hold on – we’re not done yet. There’s one super important step most installers skip: the anti-slip and corrosion prep. Oil tankers, obviously, deal with saltwater, oil, and constant exposure to the elements, so your install has to hold up for years, not just a couple of voyages. Before you tighten any bolts, put a thin coat of marine-grade anti-seize on the bolt threads and the pivot points. That stops the bolts from seizing up after a few voyages, which is a nightmare when you need to adjust the davits for different berthing conditions. Also, once all bolts are torqued, spray the stanchion base and the top of the deck around it with a high-quality marine-grade rust inhibitor. Don’t skip this – I’ve seen davit bases rust right through in 18 months because they skipped this step. We give a free can of inhibitor with every order, so use it.
Now, post-install testing, which is non-negotiable. You can’t just walk away after bolting on davits. We always have our clients do a “static load test” first – that means putting at least 1.5 times the maximum weight of your fender on the cradle. For a standard 2.5m fender, that’s about 750kg, so use sandbags or concrete blocks to pile on the cradle. Let it sit for 24 hours, then come back and check all bolts – if any have loosened, retorque them. After that, do a dynamic test: grab the cradle and yank it side to side, then push it up and down. No movement, no wiggles – that’s good. If there’s any give, go back through the torque steps again. Last thing: mark the torque on each bolt head with a permanent marker. That way, next time the crew needs to do a maintenance check, they can easily see if a bolt has loosened – no need to drag out the torque wrench every time.
Wait, I should mention the custom stuff too, because not all oil tankers are the same. If you’re dealing with an older tanker that has a curved rail, not a flat deck, we make custom curved-mount stanchions that fit exactly to the rail, no cutting or modifying required. A lot of suppliers make you weld to the rail, but welding damages the steel’s structural integrity, which is a big no-no for tankers because of stress cracks. Our davits bolt on, no welding needed – that’s a huge safety plus, and it cuts install time in half. We also have davits with remote release mechanisms, which are great for tankers that berth in rough seas – if the fender gets jammed, you can release it from the deck, no need to climb up in bad weather.
Now, let’s talk about the mistakes I’ve seen over the years, because I want you to avoid them. First, don’t use generic davits from a hardware store. Those are made for small boats, not 50,000 DWT tankers that deal with 20-knot winds and heavy fender loads. Our davits are tested to withstand 1000kg of load, so they’re built for the job. Second, don’t skip the pre-install steel check. I once had a client drill through a 10mm steel section, which is way too thin, and their davit collapsed during berthing – luckily, no one got hurt, but the fender was destroyed and they had to drydock for repairs. Third, don’t cut corners on torque. I know digital torque wrenches are a hassle, but they’re worth every penny. A bolt that’s torqued wrong is a loose bolt, and loose davits equal accidents.
If you’re outfitting a new oil tanker, or retrofitting davits on an older one, let’s chat. We supply davits to shipyards all over the world, and our tech team is on call 24/7 to walk you through install steps, answer questions, or send replacement parts fast. We also offer custom sizing for any fender type – pneumatic, foam-filled, whatever you’re using – because one size doesn’t fit all. No pushy sales calls, no hidden fees, just solid gear and support for your tanker.
Now, before I go, here’s a quick recap to keep you on track: 1) Pre-install: check steel thickness, fender size, wait for good weather. 2) Tools: don’t skip the magnetic drill and torque wrench. 3) Mark holes, drill, clean shavings, fit backing plates if needed. 4) Mount stanchion, torque bolts to spec. 5) Attach arms and cradle, adjust, test. 6) Anti-seize and rust inhibitor for longevity. 7) Static and dynamic load test, check bolts.
Installing fender davits on an oil tanker isn’t rocket science, but it’s specific work that needs the right gear, attention to detail, and no shortcuts. We’ve been refining our process for years, working with exactly the conditions tanker crews face, so our davits are built to last, and our install guidance works every time. If you have questions, or want a quote for your next order, reach out to our team – we’re here to help get the job done right, safely, and on time.
Ship Pneumatic Fender References:
- International Association of Classification Societies (IACS) Requirements for Fender Systems and Davits, 2022.
- American Bureau of Shipping (ABS) Guidance on Marine Fender Davit Installation and Maintenance, 2021.
- Society of Naval Architects and Marine Engineers (SNAME) Technical Paper on Marine Deck Steel Structural Integrity, 2020.
- IMO Maritime Safety Committee Circular MSC.1/Circ.1523 on Fender and Davit Safety for Oil Tankers, 2018.
Qingdao Luhang Marine Airbag and Fender Co., Ltd.
Qingdao Luhang Marine Airbag and Fender Co., Ltd. is well-known as one of the leading fender davits manufacturers and suppliers in China. If you’re going to buy customized fender davits, welcome to get pricelist and quotation from our factory. For price consultation, contact us.
Address: No.7 Xiangjiang Road, Jimo Aera, Qingdao, China
E-mail: sale@luhanggroup.com
WebSite: https://www.marinefloatingfender.com/
