{"id":51688,"date":"2026-04-17T23:07:27","date_gmt":"2026-04-17T22:07:27","guid":{"rendered":"https:\/\/maritimehub.co.uk\/?p=51688"},"modified":"2026-04-17T23:07:27","modified_gmt":"2026-04-17T22:07:27","slug":"tug-operations-from-the-deck","status":"publish","type":"post","link":"https:\/\/maritimehub.co.uk\/tug-operations-from-the-deck\/","title":{"rendered":"Tug Operations from the Deck"},"content":{"rendered":"
\n

ON DECK -> Mooring, Anchoring & Towing<\/p>\n

Position on Deck<\/strong><\/p>\n

Operation Group:<\/strong> Mooring \/ Towing<\/p>\n

Primary Role:<\/strong> Safe connection, monitoring, and release of harbour and escort tugs during manoeuvring operations<\/p>\n

Interfaces:<\/strong> Bridge team, tug master, mooring party, pilot, port control, winch operators<\/p>\n

Operational Criticality:<\/strong> Absolute \u2014 loss of control of a tug connection can result in capsize, parting, or uncontrolled ship movement within confined waters<\/p>\n

Failure Consequence:<\/strong> Towline parts under load \u2192 snapback zone fatality or tug girting \u2192 tug capsize \u2192 crew loss and vessel grounding in the approach channel<\/p>\n<\/div>\n

The tug does the pulling. The ship provides the load. The deck team provides the link between the two \u2014 and every failure lives in that link.<\/em><\/p>\n

Introduction<\/h2>\n

Tug operations occupy a peculiar space in deck work. They happen frequently enough to feel routine. They involve another vessel’s crew doing most of the dynamic work. And they are over quickly \u2014 a twenty-minute make-up, a transit, a release. This rhythm breeds a dangerous familiarity.<\/p>\n

But the forces involved are enormous, the snap-back zones lethal, and the margin between a controlled connection and a catastrophic one is measured in seconds of inattention. A girting tug does not send a warning. A towline under asymmetric load does not creak politely before it parts. The deck team standing on the ship’s end of that arrangement is the last line of physical control \u2014 and often the first line of consequence when something fails.<\/p>\n

This article addresses what the deck team actually does during tug work: the make-up, the monitoring, the release, and the emergency contingencies that must be planned before the messenger ever goes over the side. It is not about tug handling theory. It is about what happens at the fairlead, at the quick-release hook, and in the danger zones that no one marks with paint because everyone assumes everyone knows.<\/p>\n

Contents<\/h2>\n
    \n
  • 1. Making Up the Tug \u2014 Messenger, Towline, and the Arrangement That Matters<\/li>\n
  • 2. The Insurance Wire, Bridle, and Spring \u2014 What They Do and What They Don’t<\/li>\n
  • 3. Where to Stand and Where Not to Stand<\/li>\n
  • 4. Direct Tug vs Indirect Escort \u2014 The Deck Perspective<\/li>\n
  • 5. Who Is Actually in Charge<\/li>\n
  • 6. Watching the Towline, Watching the Tug<\/li>\n
  • 7. Planning the Release Before Making Up<\/li>\n
  • 8. Emergency Release \u2014 Quick-Release Hooks and Their Limits<\/li>\n
  • 9. Why Tug Operations Look Routine Until They Are Not<\/li>\n<\/ul>\n

    1. Making Up the Tug \u2014 Messenger, Towline, and the Arrangement That Matters<\/h2>\n

    The sequence is simple in description and unforgiving in execution. The tug approaches. A heaving line goes across \u2014 or more commonly the tug sends up a messenger. That messenger is connected to the tug’s towline, which is then heaved aboard and placed on the ship’s fitting: a bollard, a set of bitts, or a quick-release hook.<\/p>\n

    The messenger is typically a light polypropylene or soft line. It floats, it handles easily, and it is not the towline. That distinction matters because crews sometimes heave up the messenger with the urgency of handling a working line. The messenger needs care, not speed. If it fouls on a fairlead lip or chafes on a chock edge during heaving, the operation stalls at the worst possible moment \u2014 with the tug in close attendance and the ship still making way.<\/p>\n

    The towline itself \u2014 whether the tug’s own synthetic line or a wire pennant \u2014 arrives with considerable weight. Getting it up and onto the fitting requires coordination with the winch or capstan. There is a temptation to use the ship’s mooring winch to heave the towline directly, which works until the tug surges or the towline weight exceeds what the warping drum can hold without riding turns.<\/p>\n

    The correct fitting matters. A towline placed on an undersized bollard or wrapped around bitts without sufficient figure-of-eight turns is not secured. It is waiting. The SWL of the fitting must exceed the anticipated maximum bollard pull of the tug, with margin. If a quick-release hook is used \u2014 and it should be whenever one is available and serviceable \u2014 the towline eye must seat fully in the hook’s jaw. A partially seated eye under load is an ejection hazard, not a connection.<\/p>\n

    A towline that looks fast is not the same as a towline that is fast.<\/em><\/p>\n

    2. The Insurance Wire, Bridle, and Spring \u2014 What They Do and What They Don’t<\/h2>\n

    On larger vessels, particularly tankers and bulk carriers, the tug connection may involve more than a single towline to a single point. The insurance wire \u2014 sometimes called the safety wire or gob wire \u2014 is a secondary connection intended to prevent the tug’s towline from falling into the water if the primary connection parts or is released. It is not a working line. It does not take load in normal operations.<\/p>\n

    This distinction is frequently misunderstood. The insurance wire is a recovery aid and a fouling prevention measure. If crews treat it as a backup towline, they size it wrong, they lead it wrong, and they create a secondary snapback hazard where none needed to exist.<\/p>\n

    A bridle arrangement splits the towing load across two points on the ship’s bow or stern, distributing force and reducing point-loading on any single fitting. It is more common in ocean towing than harbour work, but some port configurations and terminal requirements mandate it. The deck team must ensure both legs of the bridle are equal in length and that neither leg bears against a chock edge at an angle that will saw through it under cyclic loading.<\/p>\n

    Spring connections \u2014 where the tug makes fast alongside on the ship’s shoulder \u2014 change the geometry entirely. The tug pushes and pulls from a position roughly parallel to the hull, and the connection point is a ship’s bollard amidships or at the quarter. The forces are lower, the snapback zones different, and the risk shifts from parting to crushing \u2014 the tug rolling against the hull, fenders failing, the tug’s crew exposed on their own deck.<\/p>\n

    Every arrangement has its own failure mode. The deck team must know which arrangement is being used before the tug comes alongside, not after the messenger is already on the drum.<\/p>\n

    3. Where to Stand and Where Not to Stand<\/h2>\n

    Snapback zones in tug operations are not theoretical. They are geometric. A towline under tension stores energy proportional to its elasticity and the load applied. When that line parts, the energy releases along the line’s axis and in an arc determined by the lead through fairleads and over chock edges. Anyone standing in that arc is hit with a force that no hard hat or lifejacket will mitigate.<\/p>\n

    The primary danger zones are directly behind any fairlead or chock the towline passes through, directly in front of the bollard or hook where the towline is made fast, and anywhere along the towline’s run between the ship’s side and the fitting.<\/p>\n

    If a person can see the towline, the towline can reach that person.<\/em><\/p>\n

    This is the practical rule, and it errs on the side of caution deliberately. During make-up and release, personnel must be positioned to handle the line but must withdraw the moment the towline comes under load. The officer in charge of the operation must physically confirm that no one is standing in a snapback zone before reporting to the bridge that the tug is fast or that the release is ready.<\/p>\n

    Tug operations frequently coincide with mooring operations, which means the deck is crowded. Mooring lines are being handled at adjacent fittings. People are moving between stations. In this environment, a towline parting does not just endanger the tug party \u2014 it endangers anyone on that section of deck. Segregation of the tug working area from mooring stations is not a luxury. It is a prerequisite.<\/p>\n

    4. Direct Tug vs Indirect Escort \u2014 The Deck Perspective<\/h2>\n

    From the bridge, the difference between a direct tug and an indirect escort tug is a matter of vectors and hydrodynamics. From the deck, the difference is felt in the towline.<\/p>\n

    A direct tug pulls in the conventional sense \u2014 ahead, astern, or at an angle to the ship’s centreline. The towline tension is relatively steady, the direction predictable, and the load corresponds to the tug’s bollard pull. The deck team can see the tug, see the line angle, and anticipate changes as the pilot adjusts the manoeuvre.<\/p>\n

    An indirect escort tug uses hydrodynamic forces generated by its hull and skeg at speed, positioned at an angle to the ship’s track. The resultant force on the towline can significantly exceed the tug’s static bollard pull. The line angles change dynamically, and the load is not intuitive from the deck \u2014 the tug may appear to be doing very little while the towline tension is extreme.<\/p>\n

    The deck team’s concern with indirect mode is primarily about the fitting. The loads generated in indirect escort work can exceed the SWL of fittings that are perfectly adequate for direct towing. If the ship’s towing arrangements were designed for harbour assist at six knots, they may not tolerate an escort tug generating 80 tonnes of steering force at twelve knots.<\/p>\n

    The other concern is chafe. Indirect mode involves continuous lateral load on the towline where it bears against the fairlead. This is not a momentary peak \u2014 it is sustained. Chafing gear must be in place before the escort begins. It cannot be applied once the towline is under load.<\/p>\n

    An indirect tug at speed generates forces the deck fittings may never have been tested against.<\/em><\/p>\n

    5. Who Is Actually in Charge<\/h2>\n

    The tug master controls the tug. The pilot advises the ship’s master. The ship’s master has overall command. And the deck officer at the tug station has immediate authority over the connection point.<\/p>\n

    In practice, this hierarchy dissolves into radio chatter, hand signals, and assumptions. The tug master assumes the ship’s crew will release when told. The pilot assumes the tug is fast when the deck reports it. The deck officer assumes the bridge knows the towline is chafing. Assumptions are the medium in which tug casualties occur.<\/p>\n

    The deck team must understand one principle: the ship is the load, not the operator. The tug applies force. The ship receives it. The connection is on the ship. The release is on the ship. If anything at the connection point is wrong \u2014 the towline is chafing, the hook is not fully engaged, the line angle is exceeding the fairlead’s design limit \u2014 the authority to stop the operation rests with the person standing at that fitting.<\/p>\n

    No tug master can see the state of the connection from the tug’s wheelhouse. No pilot can assess chafe from the bridge wing. The deck officer at the station is the only person with eyes on the actual link between the two vessels. That is not a supporting role. It is the critical role.<\/p>\n

    6. Watching the Towline, Watching the Tug<\/h2>\n

    Once the tug is fast and working, the deck team’s task is monitoring. This sounds passive. It is not.<\/p>\n

    The towline must be watched for chafe at every bearing point \u2014 fairlead, chock lip, bulwark edge. Synthetic lines show chafe as a furring of the surface fibres. Wire shows it as broken strands or a flattening of the lay. Both can be seen, but only if someone is looking. A deck team that makes the tug fast and then walks away to the next task has abandoned the operation at its most critical phase.<\/p>\n

    The tug itself must be watched. A tug that is heeling excessively, that is beam-on to the ship’s track, or that appears to be losing power is communicating a problem that may not come through on the radio. Girting \u2014 where the towline pulls the tug beam-on and the hydrodynamic forces roll it \u2014 happens quickly and is often the precursor to capsize. The deck team may see the tug’s deck edge going under before the tug master has time to transmit.<\/p>\n

    Watch the towline. Watch the tug. Do not take eyes off either.<\/em><\/p>\n

    If the tug signals for slack, the deck team must be ready to pay out. If the tug signals an emergency, the deck team must be ready to release. These are not responses that can be improvised. They require someone stationed at the fitting with a clear understanding of the release procedure and the physical ability to execute it immediately.<\/p>\n

    7. Planning the Release Before Making Up<\/h2>\n

    The release must be planned before the tug is made fast. This is not a procedural nicety. It is the difference between a controlled disconnection and a crisis.<\/p>\n

    Planning the release means confirming the quick-release hook is operational before the towline eye is placed in it. It means verifying the release mechanism \u2014 whether pneumatic, hydraulic, or manual \u2014 has been tested and that the release line or trigger is accessible and unobstructed. It means identifying who will execute the release and confirming that person understands the sequence: signal from bridge or tug, confirm clear of snapback zone, release, report.<\/p>\n

    It also means agreeing the release point with the bridge. At what stage of the manoeuvre will the tug be let go? Before the first mooring line is ashore? After the headline and stern line are fast? During the turn? This is not the deck team’s decision, but the deck team must know the answer in advance so that the release station remains manned and ready at the right moment.<\/p>\n

    A tug left fast too long complicates mooring. A tug released too early leaves the ship without assist in a critical phase. Both outcomes are avoidable with a two-minute conversation before the operation begins.<\/p>\n

    The time to discuss the release is before the messenger goes over the side. After that, events set the timetable.<\/em><\/p>\n

    8. Emergency Release \u2014 Quick-Release Hooks and Their Limits<\/h2>\n

    Quick-release hooks are designed to release a towline under load. That is their entire purpose. And yet they fail with troubling regularity.<\/p>\n

    The reasons are maintenance and testing \u2014 or more precisely, the absence of both. A quick-release hook that has not been exercised under load between port calls may not release when needed. Corrosion, paint over pivot points, seized pins, degraded hydraulic seals \u2014 all of these are invisible until the hook is asked to do its job and does not.<\/p>\n

    The OCIMF and ISGOTT guidelines specify testing and maintenance intervals. Class societies have requirements. Flag states have requirements. None of this matters if the hook has not physically been cycled and load-tested. A visual inspection of a quick-release hook tells an inspector that it exists and is painted. It does not tell anyone that it works.<\/p>\n

    Manual release \u2014 the sledgehammer and pin arrangement still found on older tonnage \u2014 requires a person to stand within the snapback zone and strike a retaining pin while the towline is under load. The geometry of this action is inherently unsafe. It exists as a last resort, and it should be treated as one, not as a standard operating method because the hydraulic release was defective three ports ago and no one raised a deficiency.<\/p>\n

    P\u00e9lican hooks, Karm forks, towing hooks with integrated release mechanisms \u2014 each has specific operating limits. The maximum load at which the hook will release is not infinite. A towline loaded beyond the hook’s release capacity will not release regardless of the mechanism used. The hook becomes a fixed point, and the only way to disconnect is to cut the towline \u2014 an operation that requires time, cutting equipment, and proximity to a line that is storing enough energy to kill.<\/p>\n

    A quick-release hook that has never been tested under load is an ornament, not a safety device.<\/em><\/p>\n

    9. Why Tug Operations Look Routine Until They Are Not<\/h2>\n

    Every port call involves tugs. Every tug operation follows broadly the same sequence. The messenger, the towline, the hook, the transit, the release. Thousands of times a year across the fleet without incident. This frequency is the problem.<\/p>\n

    Routine breeds abbreviation. The toolbox talk becomes a formality. The snapback zone briefing is skipped because everyone has done this before. The quick-release hook is assumed serviceable because it was serviceable last time. The release plan is not discussed because the pilot will just say when. The tug station is left unmanned because the AB is needed on the mooring winch.<\/p>\n

    Each of these shortcuts removes a layer of control. Individually, none of them causes a casualty. Collectively, they create the conditions for one. The towline parts on a day when the AB is not at the station to warn the bridge. The hook fails to release on a day when the tug is being girted and the tug master needs two seconds of response, not two minutes. The snapback zone is occupied by a seaman who was never briefed because the toolbox talk was a signature on a form.<\/p>\n

    Tug casualties \u2014 tug capsizes, towline fatalities, uncontrolled releases \u2014 share a common investigation finding: the operation was considered routine by all parties. The word appears in almost every report. It is the most dangerous word in maritime operations.<\/p>\n

    Routine is not a safety assessment. It is the absence of one.<\/em><\/p>\n

    Closing Reality<\/h2>\n

    The deck team does not drive the tug. It does not decide the manoeuvre. It does not choose the approach or the bollard pull required. But the deck team owns the connection \u2014 the physical link between a vessel of several thousand tonnes and a tug that can be rolled and sunk if that connection behaves in a way no one anticipated.<\/p>\n

    That ownership means the towline is watched from the moment it comes aboard to the moment it goes back over the side. It means the hook is tested before it is asked to perform. It means the release is planned before the make-up begins. It means people stand where they can work and withdraw to where they cannot be reached.<\/p>\n

    Tug work is not complicated. But it is consequential. The forces are real, the snapback zones are lethal, and the margin between a normal port call and a fatal one is the width of a chafe mark that nobody saw because nobody was looking.<\/p>\n","protected":false},"excerpt":{"rendered":"

    Tug work looks routine until a towline parts or a quick-release hook jams. What the deck team must actually control during tug operations.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"fifu_image_url":"","fifu_image_alt":"","c2c-post-author-ip":"2a02:c7c:2ef8:2400:931:afb1:9971:4a62","footnotes":""},"categories":[1,14],"tags":[9180,9286,92,9284,9285,9283,9287,9282],"class_list":["post-51688","post","type-post","status-publish","format-standard","hentry","category-latest","category-on-deck","tag-deck-safety","tag-escort-towing","tag-mooring","tag-quick-release-hooks","tag-snapback-zones","tag-towline-safety","tag-tug-make-up","tag-tug-operations"],"acf":[],"_links":{"self":[{"href":"https:\/\/maritimehub.co.uk\/?rest_route=\/wp\/v2\/posts\/51688","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/maritimehub.co.uk\/?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/maritimehub.co.uk\/?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/maritimehub.co.uk\/?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/maritimehub.co.uk\/?rest_route=%2Fwp%2Fv2%2Fcomments&post=51688"}],"version-history":[{"count":1,"href":"https:\/\/maritimehub.co.uk\/?rest_route=\/wp\/v2\/posts\/51688\/revisions"}],"predecessor-version":[{"id":51698,"href":"https:\/\/maritimehub.co.uk\/?rest_route=\/wp\/v2\/posts\/51688\/revisions\/51698"}],"wp:attachment":[{"href":"https:\/\/maritimehub.co.uk\/?rest_route=%2Fwp%2Fv2%2Fmedia&parent=51688"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/maritimehub.co.uk\/?rest_route=%2Fwp%2Fv2%2Fcategories&post=51688"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/maritimehub.co.uk\/?rest_route=%2Fwp%2Fv2%2Ftags&post=51688"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}