Ground Tackle Details for PCTC

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About 10 shots of anchor chain from a PCTC 
A few details about the ground tackle of a 6500 unit PCTC (Pure Car Truck Carrier or informally a car carrier) - a 200 meter ship

On all ships the term ground tackle refers to a vessel's anchors, chain and windlass.

The anchor:  The anchor type is AC-14    The weight is about 8 tons

AC-14 Anchor

The chain: The chain consist of links, the type of link is called stud link, the size, which is the diameter of the wire used to form the links is 81mm.   The length of an anchor chain is measured in shots. One shot is 15 fathoms or 90 feet (27.4 meters).

Ship's anchor chain ranged out onto the drydock

The port anchor chain is 11 shots - 990 feet or about 300 meters  - total weight is 44 tons.
The starboard anchor is 10 shots - 900 feet or about 274 meters - total weight is 40 tons.

The weight of a 81mm diameter chain is 0.144 tons/meter - the weight of each shot therefore is 4 tons.

Each shot is connected by a connecting link.

Connecting Link

The connection between the chain and the anchor includes a swivel, an end link and a bending shackle

The Anchor shackle and bending shackle

.  Global Security has a web page with good details here.

The Swivel

The windlass: There are two separate,   hydraulically powered  windlass, one  for each side, the windlass is capable of recovering the chain at a rate of about 1 shot (90 feet)  in three minutes.

Scope refers to the amount of chain used at anchor - that will be the next post: Scope - Amount recommended for anchoring.

K.C.

Ro/Ro Vessels dificulties in wind underway and at anchor

A 200 meter long  PCTC upbound Westerschelde River (photo by K.C.) 

From: The Nautical Institute Marine Accident Reporting Scheme MARS Report No 190 August 2008



Ro-ro ships – manoeuvring difficulties

An inbound pure car and truck carrier (PCTC) was approaching the pilot station at her scheduled time, in very confined waters. A gale warning was in force and with only two miles to go to the pilot embarkation point, the wind suddenly increased and pilotage services were abruptly suspended.

The master was instructed to await further orders and decided to head back to open waters rather than wait in the confined area or anchor there. The wind caught the beam of the high-freeboard and low draught vessel, and started setting her on to the lee shore, less than two miles downwind. Using full rudder and engine power, and transmitting appropriate signals on the air horn and VHF radio, the master just managed to turn the ship’s head into the wind and execute the 180-degree turn and head out to open sea.

Once out of the lee of the land, the full force of the gale caused the ship to move sideways at about five knots, even with the engine going on harbour full ahead. The vessel remained stubbornly beam on to the wind despite all attempts to heave to with the head into the sea and swell. This type of vessel has been rightly described as a ‘ping-pong ball on the water’ and under high wind conditions, ro-ros are almost impossible to control or manoeuvre.

At the first indication of approaching strong winds, masters of ro-ros and similar high-sided vessels must not hesitate to leave port or confined waters and anchorages and head out to open sea. Maintaining a safe position under way in the lee of a high offshore island is a safe option, provided the location and predicted movement of the weather system is known.

If sailing from port is not possible, ships have been kept alongside with continuous use of tugs, and, in uncrowded anchorages, mooring to two bower anchors may considered, but with engines in full readiness until the wind has abated.

Even with full scope of chain on both anchors, ro-ro vessels tend to yaw violently in strong winds and the ‘jerk’ at the extremity of each yaw may cause the anchors to drag, especially if the holding ground is less than ideal.

Mariners whose vessels may be navigating or lying at anchor near a ro-ro vessel in high winds, must allow for a greater margin of safety.

Lifeboats and Car Ships - unsafe at any height.

The lifeboats of two (sister) car ships can be seen in this photo (photo by K.C.)

gcaptain has posted a video of a lifeboat accident. It looks to me like the releasing gear may not have been fully locked. Here good article about this problem The Lifeboat Imbroglio by Captain Paul Drouin. (PDF) From that article:

The OCIMF survey also showed a general lack of confidence by seafarers in the hook/release gear.

Lack of confidence, that's one way to put it.

The article confirms what I have often suspected, since 1990 lifeboats have killed more mariners then they have saved.

This problem has been know for several years, from the article again:

Finally, what can be said about the lamentable time lag of the imbroglio? As early as 1994, the OCIMF survey into lifeboat accidents was right on the mark. Yet here we are, 14 years later and more than 20 years after serious accidents began to occur with lifeboats still grappling with the same issues.

On a car ship the problem is not launching it's recovery, try hooking up a boat with 90 feet of wire hanging from the davits. Imagine if the ship was rolling.

It seems to me the purpose of the lifeboats on a car ship is to meet SOLAS requirements, nothing more. The trick is to meet the requirements for drills without incident.

K.C.

Practices to Deter Piracy on a PCTC

A PCTC in NY Harbor
With regards to piracy attacks, a PCTC (Pure Car Truck Carrier) does not fit into the most vulnerable category of ships, those with low freeboards and traveling at low speeds, the so called "low and slow". Car ships generally are capable of 18 kts or more and have high freeboards. However taking into account the consequences of a successful takeover by pirates of an American flag PCTC manned by Americans and with U.S. Government cargo aboard, standard risk assessment doctrine requires that steps be taken to mitigate that risk.

The basic philosophy of ship security is (from USCG)

“hardening” merchant shipping targets. Even if such tactics cannot entirely prevent pirate attacks, they may prolong the time it takes for pirate groups operating from small craft to gain control of a target vessel long enough for naval or law enforcement response assets in the area to successfully intervene.

The most vulnerable points can be identified by taking a walk the length of the ship while alongside, the point of view of someone trying to board from a small boat.

In the case of a car ship there are only a few vulnerable points. How these points are best defended depends upon the layout of the ship. A combination of razor wire and well directed fire hoses (lashed so that can be used unmanned) greatly adds to the challenge of boarding a PCTC at sea.

Once at sea I am guided by a publication called "Best management practices to deter piracy in the Gulf of Aden and off the coast of Somalia"

K.C.

Discussing Piracy Risk of PCTCs.

A PCTC Alongsside

Risk Assessment consists of an objective evaluation of risk in which assumptions and uncertainties are clearly considered and presented. (Wikipedia) (FAA Risk Assessment here)

I have talked to many people with regard to what the level of risk is involved in a transit of a car ship (PCTC) through the Gulf of Aden and what countermeasures are appropriate. What I have learned is that this is an emotional issue for many people and each persons views seem more related to that persons political outlook and personality then practicality and that the passion with which the views are held and how vigorously they express those view is not related to that persons level of expertise.

I am not just talking about laymen, the views of ship's captains are all over the map as well. My view is that the risk should be evaluated the same as other risks the ship must contend with such as fire, collision, grounding, labor troubles, weather and so on. (and on and on)

In the case of a piracy attack on a PCTC running at full speed I believe we are dealing with a risk with a large potential loss and a low probability of occurring. Appropriate countermeasures should be evaluated using cost and benefits analysis. Issues with regards to the use of deadly force and the use of lethal vs non-lethal weapons should be resolved at company level and shipboard discussions are generally not worthwhile nor are they particularly enlightening.

When I encounter a person who knows very little about the reality of the situation, assumes that I have no understanding and is determined to educate me, I change the subject and offer them a cup of coffee




K.C.

Bulk Carrier in Group Transit Taken - Car Ship Chased

From EagleSpeak (in comments)

German bulk carrier hijacked in the Gulf of Aden
05/05/2009 18.46 GMT

A German owned and German managed bulk carrier this afternoon was hijacked in the Gulf of Aden in a position approximately 120 nautical miles north of Boosaaso in Somalia (1322N 04923E). The vessel, carrying a load of 10.000 tons of rice, was sailing in the transit corridor and was picked out of a group transit within only a few minutes. A helicopter from the closest warship was too late to prevent the ship from being hijacked. The crew of 11 sailors is believed to be unhurt.

05/05/2009 11.27 GMT
Pirate Attack
Somali Basin (02 38S,053 49E)
Two skiffs chased a vehicle carrier underway and attempted to board her several times. Vessel made evasive manoeuvres and escaped from the pirates. The skiffs aborted the attempt. All vessels are advised to remain vigilant.

Fairplay article here

Vehicle Carrier usually refers to a car ship or PCTC

K.C.