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Re: Marine Engineering

Posted: Wed Aug 12, 2020 8:35 pm
by ivorthediver
Keith , I was asking Harry for some help on the formula for " Rating " winches used for the use of Ships Anchors and cable weights..... for the use of ...
and wondered how this was determined or perhaps a formula used .......do you know how to work this out ?

The thread was on ships equipment if you wish to see what we were up to ...thanks Ivor

Re: Marine Engineering

Posted: Sun Aug 16, 2020 7:50 pm
by oldsalt
Wish I could help Ivor it's not my part of ship. I do ,however , have a 1960 Babcock & Wilcox book of useful tables. There is a list of the AC current required to produce the required HP for motors.There is also a similar table for DC motors. I suppose if you knew the weight of anchor plus cable to be lifted, the force required in HP could be calculated & the motor current needed. My problem would be the lack of knowing the dimensions of a motor to produce the required HP. If the winches are steam driven then pressure, temperature of the steam needs to be known to make a similar calculation. Why has no one answered my question re throttle wheels.

Re: Marine Engineering

Posted: Sun Aug 16, 2020 10:47 pm
by jbryce1437
ivorthediver wrote: Wed Aug 12, 2020 8:35 pm Keith , I was asking Harry for some help on the formula for " Rating " winches used for the use of Ships Anchors and cable weights..... for the use of ...
and wondered how this was determined or perhaps a formula used .......do you know how to work this out ?

The thread was on ships equipment if you wish to see what we were up to ...thanks Ivor
I think its a bit more than the angle on the dangle
https://engineering.stackexchange.com/q ... t-capacity

Jim

Re: Marine Engineering

Posted: Sun Aug 16, 2020 11:15 pm
by Little h
jbryce1437 wrote: Sun Aug 16, 2020 10:47 pm
ivorthediver wrote: Wed Aug 12, 2020 8:35 pm Keith , I was asking Harry for some help on the formula for " Rating " winches used for the use of Ships Anchors and cable weights..... for the use of ...
and wondered how this was determined or perhaps a formula used .......do you know how to work this out ?

The thread was on ships equipment if you wish to see what we were up to ...thanks Ivor
I think its a bit more than the angle on the dangle
https://engineering.stackexchange.com/q ... t-capacity

Jim
That seems like a good find Hon Mod Jim

Re: Marine Engineering

Posted: Mon Aug 17, 2020 8:50 am
by jbryce1437
Little h wrote: Sun Aug 16, 2020 11:15 pm
jbryce1437 wrote: Sun Aug 16, 2020 10:47 pm
ivorthediver wrote: Wed Aug 12, 2020 8:35 pm Keith , I was asking Harry for some help on the formula for " Rating " winches used for the use of Ships Anchors and cable weights..... for the use of ...
and wondered how this was determined or perhaps a formula used .......do you know how to work this out ?

The thread was on ships equipment if you wish to see what we were up to ...thanks Ivor
I think its a bit more than the angle on the dangle
https://engineering.stackexchange.com/q ... t-capacity

Jim
That seems like a good find Hon Mod Jim
I believe the term "bare drum line pull" will find other explanations, but be prepared to get baffled 😄

https://cranetrainingexpert.com/underst ... line-pull/

Jim

Re: Marine Engineering

Posted: Mon Aug 17, 2020 8:37 pm
by ivorthediver
Well lads all I can say in response to this is" I wish I had stayed on at school those extra two weeks :oops:

Re: Marine Engineering

Posted: Mon Aug 24, 2020 9:43 pm
by oldsalt
Wow, I thought it was just a round thing the Chippy wrapped the cable round.

Re: Marine Engineering

Posted: Wed Aug 26, 2020 10:50 pm
by Little h
NavyLookout Retweeted; a series of 11 tweets by a Naval Engineer that may be found to be of interest!!

Note:-
6/ reminds me of the QNLZ R08 Basin Trials that failed to identify that a bolt(s) on one of the prop blades had not been torqued down properly etc etc ... thus the need for full sea trials.
&
8/ anchor capstans get a mention (topical subject at the moment on this thread)

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Andrew Watkis @AndrewWatkis
Been on leave for a week, but it's back to work on Monday, and that means it's nearly time for a Basin Trial. But what is that I don't hear you ask? 1/
7:57 am · 15 Aug 2020·Twitter for Android

Andrew Watkis @AndrewWatkis
In the @RoyalNavy a Basin Trial is a demonstration to the Command (the Captain) that the propulsion and auxiliary systems are ready and safe for sea after a period of maintenance or an extended time alongside. It is a comprehensive serial taking up to a day depending on class 2/
7:57 am · 15 Aug 2020·Twitter for Android

Andrew Watkis @AndrewWatkis
It usually starts several days before with the Marine Engineering Department carrying out 'SAFeRs' (Sequential Action Flow Routine ). These are a series of cards that bring all machinery from an unknown state to 24hrs notice for sea (yellow/buff); 3/
7:57 am · 15 Aug 2020·Twitter for Android

Andrew Watkis @AndrewWatkis
From 24 hrs to 4 hrs notice (blues) and 4hrs to immediate (pinks). They test valve line ups, pressures, voltages, positions, indications etc so that each system is in a defined, known condition. 4/
7:57 am · 15 Aug 2020·Twitter for Android

Andrew Watkis @AndrewWatkis
Pinks are carried out on the morning of the Basin Trial, and normally 0800 or 0900, we are good to go: an OOW on the bridge, riggers on the jetty, shore services disconnected and a full watch closed up in the SCC. When the WO ME is ready the order is given to 'Start Serial 1' 5/
7:57 am · 15 Aug 2020·Twitter for Android

Andrew Watkis @AndrewWatkis
The Basin Trial itself varies from class to class in its details, but every engine will be started and connected (electrically or mechanically) and the shafts turned, ahead and astern. This will be done at minimum speed, so you don't drive up the jetty! 6/
7:57 am · 15 Aug 2020·Twitter for Android

Andrew Watkis @AndrewWatkis
The steering gear will be started and swept from port to starboard and back. Timings, readings and measurements will be taken to check everything is operating correctly, but they key thing is the ship has demonstrated that it can be controlled and manoeuvred safely 7/
7:57 am · 15 Aug 2020·Twitter for Android

Andrew Watkis @AndrewWatkis
At the same time this is going on, safety critical secondary systems are also being proved, such as sea boats, davits and anchor capstans 8/
7:57 am · 15 Aug 2020·Twitter for Android

Andrew Watkis @AndrewWatkis
Lastly, if an Integrated Electric Propulsion ship, is demonstrating Black Out Recovery. This what happens if all power generation fails onboard (a Total Electric Failure; TLF), and is how the ship goes from being in the dark to lights back on an shafts turning 9/
7:57 am · 15 Aug 2020·Twitter for Android

Andrew Watkis @AndrewWatkis
In @HMSQNLZ this is a very robust system, controlled by EPCAMS (Electrical Propulsion Control and Management System). It's not magic, but it is very satisfying when the last breaker closes and you are 'Ready to Obey Telegraphs'. 10/
7:57 am · 15 Aug 2020·Twitter for Android

Andrew Watkis @AndrewWatkis
With completion of the trial, it's time to report to the Captain, make good any defects, secure the department, or sometimes proceed straight to sea! 11, End/
7:57 am · 15 Aug 2020·Twitter for Android

Re: Marine Engineering

Posted: Thu Aug 27, 2020 3:37 pm
by ivorthediver
My dear friend , thanks for a splendid post , and the information obtained / posted is excellent .
Whilst I am aware of what a basin trial is [ thanks to the 11 years attendance of this Forum and many related posts ] it is great to see the sequence and reaction at each juncture and what action is taken .

Yes I know OLD HAT to you old sweats but to civy's its reassuring to read and acknowledge that what you thought happened DID actually happen .

Thank you for finding this and taking the trouble to post it for me ;) its much appreciated

Re: Marine Engineering

Posted: Thu Aug 27, 2020 6:34 pm
by oldsalt
Would someone please put my mind to rest by answering my query re. ME throttles. Is the small wheel ahead or astern?