Return to Great Lakes & Seaway Shipping Great Lakes & Seaway Shipping Online
Discussion Boards
Please click to visit our sponsor
It is currently September 22, 2017, 7:13 pm

FAQ | Instructions | Help
Search for:



Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 14, 2017, 1:40 am 

Joined: December 7, 2014, 9:33 am
Posts: 156
Following up on Mr. Lafferty's earlier post - 1.32 x square root of the length of the waterline is the formula for determining the maximum "hull speed" that a vessel has. An increase in beam slightly increases the length of the waterline (the distance water has to travel around the hull), but as noted changing the length of of the hull has a lot more effect on length of the waterline, and hence hull speed.

You can get a boat to go faster than it's natural hull speed, but you are going to be using a LOT more horsepower for a minimal return.


Report this post
Top
 Profile  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 13, 2017, 6:17 pm 
The variety in propeller shp (shaft horsepower) to hull beam (width) among the converted boats had an affect on their speed. The Cliffs Victory was a streamline 62 feet wide and had 9,350 shp. The C4 conversions, such as the Tom M. Girdler, were 71 feet 6 inches wide and had 9,900 shp. The Carnahan, Falk and Red Wing were 75 feet wide and had 6,800 shp. As for speed demons, it was no doubt the Cliffs Victory was fast but there is a subtle account or two of the C4 conversion Charles M. White (which was just like the Tom M. Girdler), achieving a faster time empty than the Victory from the Soo Locks to Duluth.


Report this post
Top
  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 12, 2017, 9:19 pm 
Darryl, answers to your questions, A: the engineers kept watch and check of the propeller shaft and bearings and seals. B: the shaft was in a tunnel area of the double bottom of the hull, accessible from the engine room, with the cargo hold above it. C: there wasn't any loss of horsepower, just a longer propeller shaft is all.


Report this post
Top
  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 12, 2017, 10:59 am 

Joined: March 13, 2010, 10:51 am
Posts: 938
Quote:
Over the years the Cliffs Victory and the C-4 conversion became well known for their speed. However, what about the other saltwater conversions such as the Leon Falk Jr., Paul H. Carnahan, Red Wing, etc.?

The vessels you cite retained T2-SE-A1 tanker aft sections and machinery (the Carnahan and Falk retained the bow and pilothouse) but had wider midsections inserted (75' versus the T-2's 68' beam). Their turbine-electric drives as T2s gave them a top speed of about 17.2 mph (15 knots), while the VC2 turbine-driven Victory ships made 18.5 mph (17 knots). The Cliffs Victory attained over 20 mph on its trials (probably for the reasons I outline below). I don't know if the increase in length negated the effect on speed caused by the wider beam, but the somewhat awkward transitions between the bow and stern with the wider midsection could not have helped the hydrodynamic efficiency of the hulls of the T2 conversions, perhaps hindering their speed.


Report this post
Top
 Profile  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 12, 2017, 7:06 am 
Thanks for the information on the lengthening question!

Over the years the Cliffs Victory and the C-4 conversion became well known for their speed. However, what about the other saltwater conversions such as the Leon Falk Jr., Paul H. Carnahan, Red Wing, etc.?

Growing up, I only saw the Cliffs Victory on two occasions. The last time I saw this vessel it was passing downbound at Marine City on a dreary rainy day in 1981, conditions that for some reason always seemed to bring out certain tones of the unique Cleveland Cliffs color scheme to me. Therefore, I was lucky to catch a glimpse of this ship during its final season of operation. It was truly one of those vessels that had a style to it that implied it was cutting effortlessly through the water.


Report this post
Top
  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 11, 2017, 11:52 am 
Beam seems to have more effect on speed than does length


Report this post
Top
  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 11, 2017, 11:42 am 

Joined: March 13, 2010, 10:51 am
Posts: 938
Quote:
It seems logical that the addition of the mid-section and the extra tonnage carried after the lengthening had to affect the vessel's speed and/or fuel consumption as it would have required more power to move the greater mass over the same distance.

It seems logical, but isn't so. The lengthening of a vessel generally causes no change in speed and often an increase in speed, all other factors equal, since the resistances and drag set up by the bow wave and stern wave and their interactions are changed appreciably, leading to the improvement of the hull's efficiency. This is a phenomenon of naval architecture known since the late nineteenth century and examined in detail then by famed American naval architect David Taylor. The whole purpose of the "bulbous" bow is to modify the flow of water along the sides of a ship to replicate the advantages it would have if it were longer.

Cleveland Cliffs chose a long but thin hull for optimal speed rather than a wider hull for optimal carrying capacity, reasoning (when Bunker C was a lot cheaper) that more trips per season would yield more annual tonnage than fewer trips but larger trip capacity, and be overall more economical.

As for the shore damage issue:


Attachments:
TMJ 13Jun51 3.png
TMJ 13Jun51 3.png [ 126.9 KiB | Viewed 1333 times ]
Report this post
Top
 Profile  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 11, 2017, 9:34 am 
It seems logical that the addition of the mid-section and the extra tonnage carried after the lengthening had to affect the vessel's speed and/or fuel consumption as it would have required more power to move the greater mass over the same distance.

As far as the wake issues along the rivers, this was a much less regulated problem during the 1950s/60s as there are many stories of ships like the Cliffs Victory and the Republic C-4s throwing large wakes into peoples property. Even during the 80s I remember seeing pretty large wakes being thrown by upbound ships at the Algonac State Park while overtaking other vessels. One particular example involved the Edwin H. Gott passing the C. L. Austin as they passed the small beach at the park. The 1,000 footer drew the water out for a considerable distance and when it came back it nearly washed up into the parking area. This may be caused by the bottom topography of the river at that section, which seems like a good area for ships to overtake slower vessels, so I would not be surprised that such occurrences still happen from time to time.


Report this post
Top
  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 10, 2017, 2:54 pm 
When you have like a 200 foot long propeller shaft: A) whose job is it to check on it regularly? B) Did the shaft stick up into the aft cargo hold or was it below the cargo deck? C) And when they have the engine so far from the prop, does it require more horsepower? TIA


Report this post
Top
  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 10, 2017, 6:45 am 
I bet their were a lot of complaints from people along the three rivers that she traveled about wake/wash along thee shore.


Report this post
Top
  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 9, 2017, 4:50 pm 
The lengthening was added to the midsection between the deckhouses and didn't knock down the speed.


Report this post
Top
  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 9, 2017, 3:01 pm 
dont forget that was before her aft end cargo hold was added and she only carried 13,000 tons and that my friends why she is long gone she was a pig for bunker c


Report this post
Top
  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 9, 2017, 2:33 pm 
I believe the confusion to the original post was the difference in 20 hours besting the average time between Marquette and Cleveland of then current lakers rather than the actual record time between those ports up to that point, which is not revealed by the news clipping. So in the end, the Cliffs Victory clearly beat the established average time by some 20 hours while improving over the previous record by, presumably, a somewhat smaller degree.


Report this post
Top
  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 9, 2017, 1:38 pm 
Wow. I stand corrected. I'd give about anything to have had a tour on the Cliffs Victory. But I suppose most boats (pre the AAAs) were going 10 mph. D.


Report this post
Top
  
Reply with quote  
 Post subject: Re: Today in Great Lakes History -  June 8
Unread postPosted: June 9, 2017, 10:37 am 

Joined: March 13, 2010, 10:51 am
Posts: 938
It was fast, especially light. From the Sandusky Register Star News, 8 June 1951, 16.


Attachments:
Sandusky Register 9Jun51  16.png
Sandusky Register 9Jun51 16.png [ 156.83 KiB | Viewed 2161 times ]
Report this post
Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next

All times are UTC - 5 hours




Return to Great Lakes & Seaway Shipping  
Copyright Boatnerd.com All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Use of this site is based on the Terms of Use
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group