This is an extract off our MPX which had to be signed by the Master. This is Port specific and there are many variations.
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Spo,
Two really interesting documents. Some observations.
- It is noteworthy that prior to January 2025 there were no requirements for changes between pitch command and pitch setting to be alarmed nor a requirement that there was to be no change in thrust.
- Within the accident analyses in the thesis, none of the failures were alarmed. On one occasion, the duty engineer rang the bridge enquiring about the differential.
- Within both the accidents and simulations, the employment of the emergency stop(s) did not occur.
From this, it can be reasonably assumed that there was no audible alarm for pitch differential fitted to the Cuauhtémoc.
There will be some significant lessons learnt here.
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In my years as master of an AHTS and as master of a feeder container ship all with CPP I was lucky? enough to avoid a CPP failure that you describe.
In sum instances such as berthing in wild weather or manoeuvring off a rig in deep water such a failure could have made me front page news and in the former case left a monument.
I guess that’s why I got paid the big bucks for, to wear the engineer’s oversights.
Pilots also don’t verify that the rudder is within legal limits from hard over to hard over. Or that the gyro error is actually what they claim it to be. If the Captain says the rudder is of the proper speed, and the gyro is 0.5 low, that’s what you go with.
From Sal’s video, showing a Berg control system on the bridge, it is likely (but not guaranteed) also a Berg CPP installed on this vessel.
This vessel being delivered in 1982 the machinery and equipment originally installed is likely to be of makes and types available on the market in 1980 at the latest.
I have not been able to find any info on the Berg CPPs in production at that time, but here is what Berg Propulsion AB is offering today:
The History of Berg Propulsion is very similar to that of another CPP producer at the time, A,M.Liaaen. (which was another likely candidate as CPP supplier at the time):
Source: Controllable Pitch Propellers (CPP)
PS> Liaaen’s propeller division is now part of Kongsberg Maritime. They still supply spare parts, even for older models.
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Just a few minutes ago I was going through my FB profile and found on my timeline the link to The Maritime Executive art " Two killed as Mexican Sail Traing …blah blah .
Remember reading this art ,hence it makes me wonder why some here and me an idiot too 
were so busy trying to establish if Cuauhtémoc had CPP or not .
Suspect @New3M had a good laugh seeing some crazies searching for something what was already posted here ( post 75)
QUOTE
. While detailed specifics of Cuauhtémoc’s propulsion system are not readily available, her sister ships are fitted with a controllable pitch propeller (CPP) system and a single auxiliary engine. A CPP system uses mechanical or hydraulic means to rotate the angle (pitch) of the propeller blades to move ahead (positive pitch) or astern (negative pitch). By changing the blade pitch, either direction of thrust - or no thrust at all - can be produced while the engine remains in the same direction of rotation.
END QUOTE
The said article was dated 180525 .
Well I can blame my foggy mind resulting from advanced age but there are many younger pistols here who could have noticed.
45 clicks and 4 likes . My God is it mass fogginess or hallucination ?? Beats me . Two days wasted on frantic research about the stupid CPP . This is crazy
I’m sure this will be a boneheaded question from some of you, but the CPP world is something I’ve only experienced in some sea trial work. Do these systems have an indicator that actually shows which direction and amount the pitch of the propellers? I just remember on my first old proper ship, we had an EOT and as soon as I got the proper answer back on the dial, I would look at the tachometer to see which direction and how much the prop was spinning, then log it. It was a nice double-check.
Sailing yachts under 30 meters LOA very rarely have CPPs. The smallest one made by Hundested is for 150hp and the control box is too bulky to fit in smaller yachts. What they often have is variable - not controllable pitch – props which automatically pitch up in lighter load conditions. Very useful when using mechanical AND sail power at the same time. If you’re getting some power from the sails and need only a little mechanical power you can throttle back the engine, and the prop pitches up. That will be why this vessel had a CPP, if it indeed had one. It’s quieter and more efficient.
To reduce drag, you only need a folding or feathering prop. Ability to change pitch is for the above purpose.
I mean, I didn’t post the article for no reason. I guess I should have copied the text too…maybe would have gotten more people to read it.
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Saab used to make a setup with a small diesel and a CPP. From all reports it worked quite well. I think they had them as low as 12 horsepower.
The Maxprop is a nice bit of kit, but you need to dive under the boat to change the pitch stops.
Maxprop don’t make a variable pitch prop. That’s a feathering one with manual pitch adjustment.
Check out Brunton Autoprop, which automatically varies the pitch depending on the load. Gori also make a two-speed one where the pitch can be changed under way.
The CPP propellor discussions are interesting I knew nothing about them . I learned about boat handling at a very young age, small ones, then 18 years old on a COE Hydrographic survey boat. She was 65 feet 49 GRT twin Detroit 610’’s with reverse gears. Well maintained.
The operator was a very experienced old timer. 1965 he was in his 60’s had grown up on Chesapeake Bay passenger steamers. Always docked the boat as if it was single screw. Alongside flat close enough deckhand could get a spring line on the dock then then in and out of gear boat moving very slowly. Asked why he said “ don’t count on any engine responding” “ leave room to steer around if she won’t back down”
Never forgot the lesson and personally was on a 60 some foot vintage yacht docking the same way blow an air line & engine would not shift into reverse. Captain took a big circle then put me in engine room manually shifting to his shouted commands. Since, my own boat lost her hydraulic steering backing into a slip. Was able to get her out going ahead, then alongside another dock rudder amidships reverse into the current bumping in and out walking to port.
Saw all sorts of operating error accidents in the Coast Guard and working shore operations for ocean carriers equipment failure accidents with ocean vessels. I was with American Export when the Sea Witch collided under the Verazino bridge. Knew Captain Patterson personally a fine man and very good master. Broken rudder, and bad luck he did all a master could do anchors, reversing, danger signals and saving his crew. Unfortunately dying of a heart attack while waiting to be taken off by the fire boat.
Last was working on shore for a Scandinavian carrier when one of our ships bow flare hit a container crane docking, knocking it down and starting a small fire. Came in too much angle too fast, reverse walked the stern to port made the angle worse . Assist tug on the bow set up to push no line up could not pull & assist.
Point of all this is equipment can fail anytime. Operator, Master, Pilot, Tug, Ships crew on the anchor, shore management approving assist work in advance must be prepared to react when it does.
Mechanical aside human error is the root cause this incident.
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That concept is deeply embedded into the maritime industry. Some operations are higher risks then others and some operations have risks that are not correctly identified but virtually every operation at that level includes the implicit assumption that equipment can and will fail.
A similar thing happed on a tug I was on as C/M. We were leaving the Duwamish Shipyard in Seattle and the pneumatic controls lines ahead / astern had been switched when reinstalled.
The captain put the throttle (fixed single screw) astern and the tug started creeping ahead. The assumption was it was due to current from the river. He instinctively increased the throttle, tug surged ahead into some shipyard equipment.
In that case it wasn’t an assumption that equipment could not fail but that the failure mode was such that it wasn’t recognized for what it was.
Absolutely correct.
Human error is a significant factor in most accidents and can be as high as 85% according to estimates.
Human error was the primary causation in this incident.
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Last from me on the subject. I have a little East River experience a lot of tide and current experience. A slip is protected . Get outside the vessel is subject to the current. Direction and flow is not as precise as the published data would have you believe.
Time of ebb or flood varies from prediction depending on wind direction run off upstream etc. Direction in a complex waterway emphasized textcan move two ways same time. Tide change starts one side works it’s way to the other. Wind can make it move one way deep the other on top.
Have sailed out of the East river marina on FDR drive about 24th street. Farrell yacht, was the host on customer cruises. Captain very experienced ex New Bedford trawler Captain . Observing with some knowledge how he handledemphasized text her . My side job was was 20 years CG Reserve augmenting at stations , Coxswain & 1st Class BM, watched his methods
He had all guest sitting until out of the slip and the boat was underway. Sometimes had to use a lot of throttle to get her settled down. Most people way over estimate current speed or don’t have a clue. East river could easily been have been flooding 3 knots and the fixed position current gauges will not have recorded it.
The river calls for Caution and careful planning.
I read the article, but it was not clear which type/manufacture of CPP was installed on this vessel.
It now appears likely that the propulsion system presently installed is from Berg, but whether that is from original, (1980s) or a later replacement is not clear.
With a single engine (Cat D399) and a strait shaft, there are most likely a reduction gear and possibly clutch, involved in the propulsion train. (More that can go wrong)
CPP is not a new invention, (1930s) nor more prone to faults than other propulsion systems.
IIRC; in case of a problems the default position for the Liaaen CPPs were “neutral”. (Don’t know if that apply to Berg CPPs)
An engine telegraph would be used for Engine room control of pitch and/or engine RPMs
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The low-speed main engines I’ve worked with, if the EOT was in an ahead position and the engine was turning astern (or vice versa) an ear splitting alarm would go off and the “Wrong Way Alarm” would light.
Wrong Way Alarm**
If the engine rotates in the direction opposite to that ordered by the main telegraph the emergency shutdown solenoid valve is energized and a signal is sent to the governor cutting off the fuel supply to the main engine. At the same time the WRONG WAY lamp starts flashing and an alarm buzzer is activated.
From here: https://knowledgeofsea.com/main-engine-manoeuvring-control/
• Vibrations in Propeller System √
• Difficult to control the pitch √
• Forward Pitch Possible - Astern Pitch Impossible √
• Propeller Pitch or Engine RPM is varying
• Propeller Pitch Suddenly Changing at Full Speed √
• Full Astern, but very little Response in Boat √√√
• Propeller is not engaging when clutching in
• Propeller is not disengaging when clutching out √
• Warm Gearbox
• Oil temp too low
• Clutch does not engage
• Clutch does not disengage
• Clutch slips at normal load
• Oil level sinks
• Oil level increase
• Unusual noise from gear
• Engine stalling when rapid manoeuvre occurs √
• Oil leaks / Coast Guard chasing me…
The reasons listed here are known indicators and based on empirical registration. However, other occasional situations and reasons may occur and cause problems that are not in the list above !!!
√ = Troubles experienced as master on a CPP tanker & as pilot.
• Propeller suddenly changing to Full Pitch while berthing, stern line parted violently and nearly killed a linesman (Accident Report made)
• Engine stalling in rapid manoeuvres
• Full Astern very little & scaring backing response (generally poor backing power)
• Stern line tangled in the propeller while berthing
• Vibrations while berthing
• Etc …
Eh ???