MV Narrabeen's 2017 Garden Island Dry Docking in Pictures (Part 2 of 4)

Click on each image to automatically advance to the next one

Dock crews washing Narrabeen into recovery from four days of heavy grit blasting. Garnet spoil lies in piles beneath the hull along it's entire length.

Each time the Narrabeen goes into dock, the Skeg at each end (at right in the upper photo) has to be cut off by yard boilermaker. It's removal gives the riggers better clearance for chainblocks and slings whilst moving steering gear components on and off the boat. After docking, it is welded back on.

A yard boilermaker cuts off Narrabeen's aft skeg. Just before it drops, a second boilermaker will approach from the opposite site to support the skeg and prevent it from dropping down into the dock. Not a job for the unfit - the skeg weighs over 40kg and is awkward to handle, especially when hot.

For about a week, scaffolding will be in place around Narrabeen's funnel to allow painters to get in close. Only while this scaffolding is up is it possible to get this view looking down, end-on, into Narrabeen's funnel. Here are the exhaust pipes of the ship's two main engines and two generators.

A fitter removes the bolts which fasten Narrabeen's rudder and stock. First, the nuts are cracked and wound off. Then, the bolts must be backed upwards through their holes nearly completely before they can be tipped over and fully extracted. Restrained in movement both by a well-engineered joint and also by having been coated in a tar-like thread preservative, these bolts are always a challenge to remove. Each bolt weighs over 20kg so fitters use whatever means they can to move them upwards.

The lead rigger checks and rechecks the precision of his arrangement of lifting straps, shackles, lifting eyes and chainblocks before he calls in the rest of the team to commence with the removal of Narrabeen's aft rudder. This photo also shows exactly why the riggers insist upon the removal of the skeg.

Narrabeen's 2.6-tonne aft rudder is out and secured to two disused keel blocks on the dock floor. On a pallet nearby are the six sets of bolts which join it to the rudder stock, while the rudder stock itself, whose palm is seen at upper right here, will be the next removal job for the riggers at Narrabeen's aft end.

Narrabeen's aft end, with rudder removed. The palm of the aft rudder stock, still coated in black joint preservative, is seen here above the propellor hub.

With heavier grit blasting on the lower hull competed, painting crews now move in for some closer, more hands-on treatment of Narrabeen's superstructure. Abrasive polishers at work on the forward end.

On the face of it, all seems well. Narrabeen's aft rudder stock appears in good condition. It currently stands in the northern end of the dock, strapped down to a pallet, and is going nowhere. Nowhere is good. Any serious pitting or damage to this stock could necessitate it's relocation out of the dock floor and into the fitter's shop for potentially costly machining and re-survey.

Surrounded by scaffolding, Narrabeen's funnel has had it's curiously small old white lettering removed, it's surface prepped and primed, and now awaits a freshly painted black band. Shortly after that, her new, more suitably-sized white letters will be stencilled on. A welcome change for many.

Narrabeen's 307kg number three propellor blade has been unbolted and removed from the aft hub. The ship's engineer and yard fitters immediately inspect the joining surfaces to check for any signs of abnormal wear. The blade will be strapped to a pallet and remain in the dock for further testing.

Narrabeen's aft propellor hub, with the space left vacant by the recent removal of blade number three. Alteration and control of the propellor blade's pitch is achieved by the rotation of this footing via it's connection to the gallery of pressurised oil flowing to and from it through an intricate arterial supply system within the shaft.

A custom-built lifting eye, whose bolting scheme perfectly matches that of the removed propellor blade, is lowered into position and will be bolted into the shaft exactly as if it was a blade. With this valuable connection the shaft, the lifting eye will be used by riggers who will suspend the shaft by chainblocks as they extract it from within Narrabeen's aft stern tube.

Within the Narrabeen's internal void spaces lies the external shaft's actual connection to the driving portion of the shaft, coming from the main engine. This connection must be broken, and sections of shaft divided, before the riggers can begin to extract the tail section of the shaft. In this photo, the shaft is supported locally at left by a 3-tonne chainblock. At right, supported by a second chainblock, is the internal seal assembly of the stern tube. To the right of the stern tube seal will be the exiting direction of the soon-to-be-removed shaft. At the leftward extension of the shaft in this photo is the amazing SKF Coupling, which acts, in layman's terms, like a snap-type hose fitting. To disconnect the two sections of shaft, this coupling must be broken and is done so by the imposition of enormous hydraulic pressure within it (see the two grey tubes attached to the coupling?) which will force the coupling to release its grip on both sections and allow them to part. The fitters do this with air-driven hydraulic presses and regularly clock up pressures of over 30000 psi in the process.

The connection is broken and the shaft is on its way out. At right, directly in front of the fitter, is the actual and of the tail shaft which will shortly disappear into the stern tube on its way out of the vessel and into the dock. Like a severed limb, it has just been disconnected from its lifeline and will be leaking oil out of its internal gallery for days. Below the fitter at left is the SKF coupling, floating free under chainblock suspension, having released its grip from both shaft sections. To the left of the SKF coupling is the section of the shaft which leads to the main engine. Here, the fitters act as riggers as they guide the shaft out of the compartment as it slides away to the right and out through the stern tube. They maintain constant radio contact with the riggers in the dock, who are in a seperate world outside the boat but less than three metres away to the right.

Narrabeen's aft shaft begins its outward journey. The shaft extraction job puts the riggers into full flight, and this photo demonstrates exactly why the three lifting eyes had to be welded onto the hull. Directly to the left of the propellor hub is external stern tube seal assembly, which will travel out with the shaft.

Scuppers. Scattered throughout the Narrabeen's internal and external passenger decks are floor drains. They allow accumulated surface water to drain away and escape back down off the ship, back into the harbour. During heavy rains or in heavy seas when the ferries take a large amount of seawater on board, the function of these scuppers is essential for safety and, ultimately, stability. The scupper drain pipes make their out of the ship though hull openings just below the Narrabeen's sponsons. To prevent the outflow from draining down along - and staining - the hull areas below them, the scuppers are fabricated with simple spout-like projections along their lower edges called lips. Contact with pilings, wharves and other vessels can easily damage these lips and occasionally they are damaged to the point that they themselves actually block the openings cause the scuppers to back up. In a specialised operation, yard boilermakers regularly have to replace close to a third of these scupper lips on a Freshwater Class Ferry during a docking.

Narrabeen's aft propellor shaft has been almost fully extracted. To go any further, riggers must shortly transfer the suspension points completely from the ship to the crane. At left here, the load of the propellor hub is already under suspension from the dock's 60-tonne western crane which is sitting over the top of the ship. As the shaft eases out, riggers will carry out the delicate process of shifting the load from the four major rigging points on the ship to, ultimately, just the one from the crane split into two tethering points. The final stage of the lift, using just the crane, is a precision move made very complicated by the fact that the 8.5 tonne shaft refuses to sit on a level plane. The 4.7 tonne propellor hub itself weighs more than the rest of the shaft combined.

Narrabeen's shaft is now out of the stern tube. Oil still trickles from the internal network within the shaft and has to be constantly attended to by the fitters.

The full 8.7 metre length of Narrabeen's 8.5 tonne aft propellor shaft is now fully extracted from within the ship and will be eased away and down onto purpose-built stands on the dock floor.

Narrabeen's upper and lower passenger gangway are raised and lowered with a hydraulic system. The gangway systems are dismantled and serviced at each docking. Each gangway uses two large rams which drive it into the down position and retrieve it back into the up position. Also, each gangway is locked into the up position by securing cleats, one on each side, which are also driven into and out of position by two smaller rams. All 16 rams are removed and, here, taken away for servicing or replacement.

Narrabeen's two lower passenger gangways will shortly be detached from their mounting pins and taken away for servicing. Before this can happen, the area must be certified to be safe for passage when they gangways are off the ship. A barrier of scaffolding must be installed in this case. A scaffolding arrangement is deemed to be completed and certified only when the certifying tag is visibly displayed from the scaffold, seen here at bottom left of the right side photo.

Free of it's securing pins, Narrabeen's port lower passenger gangway begins is journey to away to a virtual rebuild in the yard's boilermaker shop. Both of Narrabeen's 33-year-old lower gangways are constructed of steel and their exposed undersides bear the major brunt of the sea's corrosive effects as they make their way to and from Manly 18 hours a day, seven days a week, in all weather conditions.

With the port side lower gangway now craned away, all that remains is the 'transition strip' of gangway plate which serves as a freely moving bridge between the gangway and the ship during normal operation. It moves up and down with the gangway but is not joined to it at all, resting on its own set of securing pins which must be cut off for its removal. Getting the gangways and transition plates onto and off of the ship is very tricky due to the way in which they are joined onto the ship and due also to the limited ways in which the riggers can lift them.

Scaffolding and more scaffolding is now in place in front of both of Narrabeen's upper deck passenger deck gangways in preparation for removal. Though they are constructed of aluminium and lighter than the steel lower passenger gangways, the operations required to get them onto and off the ship are no less tricky.

It was a busy day in the dock, cranewise. Narrabeen's upper and lower passenger gangways are an eight-piece set. Removing them puts riggers, fitters and boilermakers all on the same job. Some are easier to rig than others and, due to their awkward positioning on - and attachment to - the ship's side, they require elaborate safety clearance plans below them both on the ship and in the dock floor. Once off the ship, they are taken away to the boilermaker's surgical theatre.

With all vital fluid systems onboard having been drained of their oil, diesel, salt and seawater and coolant, the valves within the arterial lines of those systems are all dismounted and taken to the fitter's shop for inspection and service. The job schedule for this valve, itself over 30 years old, starts out the same as that of all the others: complete dissection.

The view from our current position on the west side of the dock's northern partition. This view puts us in our place, especially with the recent arrival of the massive HMAS Choules, berthed just outside the front caisson at upper right. Some may note that both of our masts have been lowered onto their cradles. Some with magnifying glasses will spot the yard boilermakers at work on the opposite end, in our same position. They are welding in brand new yardarms for the rigging of our house flags and ensigns.

The view to the south, from the same position, shows the massive scale of this graving dock and the way in which it is partitioned. Immediately in front of us sits the 6000-tonne centre caisson, creating the division in the dock between us and the 18000-tonne HMAS Success, over twice our length and the largest RAN ship ever to be built in Australia. This year, both HMAS Success and Narrabeen have already celebrated their 33rd birthdays.

Narrabeen's lifeboat davit is under investigation by a yard painter on suspicion of corrosive behaviour.

When painters go to work on some of Narrabeen's more remote corroded areas, they sometimes find that the base metals are nearly gone if not completely gone.

Patches of undercoating dot surfaces all around Narrabeen's hull and superstructure. As preservatives, each type of undercoating is designed specifically for the class of metal it will be applied to. Some are designed to be applied only to bare metal, while others will only adhere to existing coatings. Early next week, final coats of paint will start to appear.

Narrabeen's forward shaft, nearly fully extracted from within the hull. At this point, the dock's 60-tonne western crane is called in to join the party. The crane has taken its first hold at the propellor hub, and will now work in conjunction via radio with the dock riggers to extract it out further, to the point at which the crane can get a second, balanced hold further along the shaft. Then, the crane will take full command of the lift, ease the shaft away from the hull and over to the waiting stands just forward of the ship.

The dock's western crane driver oversees, amongst other things, the final stages of the removal of Narrabeen's forward propellor shaft. He is taking radio commands from his partner in the dock standing just beside the hub. In the very distracting distance above, the majestic waters of Sydney Harbour where the 1150-tonne Narrabeen has been going back and forth to Manly since 1984.

Rudders are actually hollow. They are fabricated from steel plate with internal bars welded in for strengthening. Due to rudders' narrow internal dimensions, it is impossible to weld these bars onto both internal faces. So the first face, shown here at left, is fabricated with the bars' welds completed onto its internal surface and displays no external evidence of these welds. The opposite face, at right, called the closing plate, is fabricated with a scheme of slots designed to couple up to these internal bars so that, when the two are pressed onto each other, the internal bars on the first side perfectly match up to the slots and partially poke through so that they can be slot welded. This is evidenced by indentations on the rudder face, shown here at right. The hole in the rudder's upper centre runs through the rudder internally and enables the rudder to be lifted. Since rudders are hollow, they are therefore buoyant and are under constant pressure to rise up. The device which is clamped on to the rudder stock between the rudder and the hull is known as the jumping ring. It is a preventative safeguard which prevents buoyancy - or any other force - from forcing the rudder upwards into the steering box, which could cause serious, potentially disabling damage, to a ship.

Narrabeen's aft rudder sits in the dock. Before it was dropped down off of the stock, it was tested for watertightness and incursion of water by a yard fitter. On the bottom face of each rudder is a drain plug. Fitters use a 56mm socket to loosen and remove the plug, looking for escaping water and either negative or positive air pressure, depending upon the rudder's internal air temperature relative to the air outside. When the plug is removed, the perfect result would be no outflow of water but instead a trickle of the rudder's internal preservative oil coating together with along a small inrush of air, confirming watertightness.

Narrabeen's steel-constructed lower gangways have completed their journey from the dock to the boilermakers' surgery theatre.

Some of the finer examples of corrosion on Narrabeen's lower gangways. The sea has had its way.

Narrabeen's aluminium upper gangways have completed their journey off-ship as well, but have wound up - in apparent banishment - in the end of the dock beneath HMAS Success, along with our anchor chains and anchor windlass.

Refurbishment of Narrabeen's upper passenger gangways calls for, to start, complete removal of existing glued-on vinyl decking.

This outer stern tube seal for Narrabeen's aft shaft spends its life underwater, on the job, acting to lock vital lubricating oil into the stern tube whilst also fighting to keep damaging seawater out.

Narrabeen's aft outer stern tube seal is pulled apart into eleven seperate pieces. It comes apart in layers, and formed within each layer is a purpose built, spring-loaded, synthetic ring seal. Four seperate new ring seals will be formed into its re-assembled structure, two for pushing oil inwards and two for pushing seawater outwards. The key to their design is that, when the shaft is fed back through the seal and the seal's assembling bolts are torqued down, the resultant pressure will activate the springs within all four seals, causing each ring seal to step up it's sealing characteristics even more. In preparation for a docking, these crucial and expensive seals probably had to be ordered a year in advance.

Liquid dye penetrating fluid is flooded down onto Narrabeen's forward propellor shaft. This is the first step in a three-step inspection process, which must take place in every docking, to check for not only internal and surface cracking but also to determine the metal's porosity, which is a direct indicator of it's health. These tests must be conducted on the shaft, rudder stock and one selected propellor blade from each end, as well as in other areas of the ship.

Once the red liquid dye has dwelled upon the surface for 20 minutes, it is wiped away completely. Then, a developing agent is sprayed onto the surface. This frost-like coating will eventually extract up and out onto the surface any red dye that has seeped into cracks or pores, resulting in visible marks that identify defects. Skilled inspectors can read any such marks like a book.

Narrabeen's number three aft blade has been dyed, polished and sprayed with the white developing agent. When asked his assessment of this blade, this was the technician's summation: "...the casting is exhibiting as-manufactured porosity. It's magnificent!" I think this is what we were hoping for.