JHOLLAND1
Titanium
- Joined
- Oct 8, 2005
- Location
- western washington state
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OT--HMS BULLFROG
- Thread starter JHOLLAND1
- Start date
- Replies 6
- Views 629
cyanidekid
Titanium
- Joined
- Jun 4, 2016
- Location
- Brooklyn NYC
thanks, interesting, but the crappy attempt at "old film" effect does detract... (they should keep the cable "fairlead" and display)
Joe Michaels
Diamond
- Joined
- Apr 3, 2004
- Location
- Shandaken, NY, USA
JHolland1:
Thank you for posting this youtube. It does seem a shame, but an inevitability, that an old steel-hulled ship in saltwater winds up as scrap. It is a rare and very costly exception to keep historic/museum ships afloat, let alone in a seaworthy condition. A cable laying ship is a rare type of vessel. This particular vessel, from the youtube, was built with two triple expansion steam engines for main engines and plenty of steam driven auxiliary machinery. The ship was built in wartime, so it is possible recip engines were chosen rather than diesels. The last steam engine driven ship in the US Merchant Marine (US MMTS, I think) was the "Meyer" (? on the spelling). The Meyer was also a cable laying ship. She was powered with Skinner Unaflow steam engines. I believe the Meyer, as well as the vessel in this post, got recip steam power for its manueverability and ability to crawl along at very low speeds.
A recip steam engine is very nearly instantly reversible, and has full power ahead or astern. I've seen marine engineers handling recip main engine reverse them as fast as the servomotor could 'throw the links over'. Being in the engine room when this kind of going from full ahead to full astern is done with a recip main engine is an experience. The whole engine room shakes violently, pipes whip and flex, you can hear the glass in some of the gauges rattling in the bezels, and any small loose items tend to get moved around. Even pens and pencils on the watch desk and the 'bell book' and engineer's logbook wind up on the floor plates.
For cable laying, a ship has to kind of crawl along paying out the cable. In the case of the "Meyer", she was converted from Skinner Unaflow steam engines to diesel-electric drive sometime in the 70's or early 80's. She got G.E. diesel engines.
The NY Power Authority laid a submarine power transmission cable across Long Island Sound. This was a cable capable of transmitting several hundred megawatts of electric power. The cable was manufactured by a division of Pirelli, in Italy. It was loaded onto a cable laying vessel right at the Pirelli plant, being spooled onto a drum in a hold of the lay vessel. The vessel then sailed across the Atlantic and into Long Island Sound, where it laid the cable. I was not involved in that particular project, but heard about it from buddies who were. The vessel had a huge specialized hold with a drum having a vertical axis. This drum wound up the cable at the factory, and then it was unspooled at the laying site. I suspect the "Bullfrog" had a similar type of arrangement. By going to diesel-electric propulsion, there is the same sort of quick maneuverability the steam engines had, but the added advantage of control from the bridge, or on deck.
The more modern propulsion systems using 'Azipods' or similar are being used in many type of vessels instead of the conventional screw propellors. These allow very precise positioning and maneuverability, and might be what the latest cable laying vessels are using. Steam propulsion of ships, short of nuclear powered vessels, is heading for extinction. Moves to get increased fuel economy and reduction in stack emissions/greenhouse gases has spelled the end of most of the remaining steam turbine powered vessels, both on the salt water as well as the Great Lakes. The "Bullfrog" was something of a survivor, being a vessel with triple expansion steam engines and steam driven auxliary machinery lasting as long as she did. Her uniqueness as a cable laying vessel was what kept her around and active long after just about every other large vessel with steam engines was long gone. In the USA, only the "Badger", a Great Lakes ferry with Skinner Unaflow engines, is likely the sole surviving vessel with steam engines. Even the old Huron Portland Cement vessels, long out of service and used as floating cement storage, have gone to the razor blades. The last of these is the "S.T. Crapo". She has a triple expansion main engine. Preserving a large old ship is one of those near-impossible things. In Europe and England, old steam ships are not only preserved, but maintained such that they can be steamed and taken out for various trips. In the USA, we have a dismal record of not preserving historic steam ships and letting them go to the razor blades. The two Liberty Ships, one on the East Coast, one on the West Coast, and the Victory ship are the exceptions. At least the "Bullfrog" went to her end in a country where quite a number of large steam vessels are kept in active service as historic vessels.
The youtube mentions that historic parts of the "Bullfrog" were saved. Hopefully, this would include the two main engines and the steam driven auxiliary machinery.
Thank you for posting this youtube. It does seem a shame, but an inevitability, that an old steel-hulled ship in saltwater winds up as scrap. It is a rare and very costly exception to keep historic/museum ships afloat, let alone in a seaworthy condition. A cable laying ship is a rare type of vessel. This particular vessel, from the youtube, was built with two triple expansion steam engines for main engines and plenty of steam driven auxiliary machinery. The ship was built in wartime, so it is possible recip engines were chosen rather than diesels. The last steam engine driven ship in the US Merchant Marine (US MMTS, I think) was the "Meyer" (? on the spelling). The Meyer was also a cable laying ship. She was powered with Skinner Unaflow steam engines. I believe the Meyer, as well as the vessel in this post, got recip steam power for its manueverability and ability to crawl along at very low speeds.
A recip steam engine is very nearly instantly reversible, and has full power ahead or astern. I've seen marine engineers handling recip main engine reverse them as fast as the servomotor could 'throw the links over'. Being in the engine room when this kind of going from full ahead to full astern is done with a recip main engine is an experience. The whole engine room shakes violently, pipes whip and flex, you can hear the glass in some of the gauges rattling in the bezels, and any small loose items tend to get moved around. Even pens and pencils on the watch desk and the 'bell book' and engineer's logbook wind up on the floor plates.
For cable laying, a ship has to kind of crawl along paying out the cable. In the case of the "Meyer", she was converted from Skinner Unaflow steam engines to diesel-electric drive sometime in the 70's or early 80's. She got G.E. diesel engines.
The NY Power Authority laid a submarine power transmission cable across Long Island Sound. This was a cable capable of transmitting several hundred megawatts of electric power. The cable was manufactured by a division of Pirelli, in Italy. It was loaded onto a cable laying vessel right at the Pirelli plant, being spooled onto a drum in a hold of the lay vessel. The vessel then sailed across the Atlantic and into Long Island Sound, where it laid the cable. I was not involved in that particular project, but heard about it from buddies who were. The vessel had a huge specialized hold with a drum having a vertical axis. This drum wound up the cable at the factory, and then it was unspooled at the laying site. I suspect the "Bullfrog" had a similar type of arrangement. By going to diesel-electric propulsion, there is the same sort of quick maneuverability the steam engines had, but the added advantage of control from the bridge, or on deck.
The more modern propulsion systems using 'Azipods' or similar are being used in many type of vessels instead of the conventional screw propellors. These allow very precise positioning and maneuverability, and might be what the latest cable laying vessels are using. Steam propulsion of ships, short of nuclear powered vessels, is heading for extinction. Moves to get increased fuel economy and reduction in stack emissions/greenhouse gases has spelled the end of most of the remaining steam turbine powered vessels, both on the salt water as well as the Great Lakes. The "Bullfrog" was something of a survivor, being a vessel with triple expansion steam engines and steam driven auxliary machinery lasting as long as she did. Her uniqueness as a cable laying vessel was what kept her around and active long after just about every other large vessel with steam engines was long gone. In the USA, only the "Badger", a Great Lakes ferry with Skinner Unaflow engines, is likely the sole surviving vessel with steam engines. Even the old Huron Portland Cement vessels, long out of service and used as floating cement storage, have gone to the razor blades. The last of these is the "S.T. Crapo". She has a triple expansion main engine. Preserving a large old ship is one of those near-impossible things. In Europe and England, old steam ships are not only preserved, but maintained such that they can be steamed and taken out for various trips. In the USA, we have a dismal record of not preserving historic steam ships and letting them go to the razor blades. The two Liberty Ships, one on the East Coast, one on the West Coast, and the Victory ship are the exceptions. At least the "Bullfrog" went to her end in a country where quite a number of large steam vessels are kept in active service as historic vessels.
The youtube mentions that historic parts of the "Bullfrog" were saved. Hopefully, this would include the two main engines and the steam driven auxiliary machinery.
Scottl
Diamond
- Joined
- Nov 3, 2013
- Location
- Eastern Massachusetts, USA
Hmmm, HMS Bullfrog.
I have to ask, was it held together with Rivets?
I have to ask, was it held together with Rivets?
Joe Michaels
Diamond
- Joined
- Apr 3, 2004
- Location
- Shandaken, NY, USA
Scotti:
You ask an interesting question. "Bullfrog" was built during WWII if I remember the youtube correctly. That was a time of transition in shipbuilding from riveted to welded construction. Given the times and type of ship that "Bullfrog" was, my thinking is the ship was put together using rivets. Rivetting was a proven thing, it was in common use and the shipyards were set up for it, moreso than welding at that time.
Looking at a ship's hull, particularly after a few decades of slathered on paint along with rusting, it is sometimes hard to discern how the hull was put together. A riveted ship's hull does not have rivet heads projecting much beyond the exterior surfaces of the hull plates. The rivets are driven in countersunk holes, with a bit of a crowning just beyond the surface of the hull plates. This gives a 'fair' surface, with less drag in the water. Were the ship's hull riveted using rivets with a projecting head (such as 'acorn', 'button', or 'pan' heads), the thousands of rivet heads projecting from the hull would add tremendous drag.
The "Bullfrog" has what is known as a 'molded hull'. I.E., the plates are formed into curves in multiple axis. The seams where the plates meet are calked to seal them and make them watertight. Calking is done with an air rivetting gun with a blunt or radius'd end chisel steel in it. The calking chisel is driven into the edge of the plate overlaying or lapping the mating plate. The calking forms a groove in the edge of the overlaying plate and upsets the metal from that plate, forcing it into the underlying plate.
After decades at sea, a ship gets to resembling a hungry old horse, showing her ribs (frames). Years in heavy seas will cause the plates to be 'stove in' between the frames. The ship goes into the yards for repairs, and often, welding is used for the repairs. Plates may be cut out to access machinery inside the hull, or thinned or stove-in plates may be cut out and new plates welded in. Usually, on a riveted hull or boiler repair, the die is cast for continuing with riveting. It is easy enough to think in terms of welded repairs or alterations. However, welding sets up stresses, and tends to 'draw' as the welds cool. This can actually open up the calking on adjacent riveted seams. It is a bit of an art to determine when to continue with riveting vs welding. "Bullfrog" was a working ship. She was likely put into the yards and repaired and modified many times over her life. I am sure if a person were to get up close to her hull and take a good look, she'd have plenty of weld bead running on her plating and maybe some riveted plating patched in.
Even in this day and age, there is at least one shipyard up on the Great Lakes at Toledo, Ohio which still does riveted repairs. There are enough older hulls still in service on the Great Lakes for this shipyard (Ironhead, I think their name or nickname is) to keep doing riveting.
40 years ago or thereabouts, I worked on a job with an older gent who had been a shipyard boilermaker, and had worked on riveted hulls. We were working together on the construction of a new coal fired powerplant. This older gent told me how he'd been in a riveting gang and paid piece-rate, so much for each rivet driven. He told me he'd been driving what he called "Liverpool Rivets". He explained these were rivets driven into a countersunk hole. The other end of the rivet had a regular head (such as an 'acorn' or 'pan' head), and was stuck thru the holes from inside the hull so the plain shank stuck outside the hull. The heater, catcher, sticker and bucker (each of these guys has a specific job in a riveting gang) were inside the hull. The driver, which this gent happened to be, was on the outside of the hull. The gang on the inside would take an orange-hot rivet and stick it in the hole so the heated end of the shank stuck outside the hull. The driver would then "get on it" with his gun, using a 'rivet snap' which had a very shallow concavity. This fellow told me he made a lot of money driving those "Liverpool Rivets", claiming they had to be driven very fast because the hull plating would suck the heat away from the driven head way faster than with an exposed head. Being on piece rate, having to move fast to drive the Liverpool Rivets meant more rivets driven per shift and more money for the gang driving them.
Riveting is a method of construction that is not so bad as it sounds. It is definitely more labor intensive and makes for more difficulties in putting something together. However, when a rivet is properly driven, it 'upsets' to lock solidly in the rivet hole, and when the rivet cools, the contraction really clamps things together. This is known as 'bearing' in engineering. Riveted construction is quite an interesting subject in its own right. Having dealt with it many times on jobs over the years, I have some familiarity with it, and a LOT of respect for the crafts who built ships, boilers, tanks, and numerous building and bridge structures and so much else using riveting. When I see an old bridge or structure or some other riveted work being cut up for scrap, I get a momentary twinge, knowing how what it took to do that riveting. Not all rivets were driven by crews with hand-held riveting guns. In the shipyards, structural shops and boiler shops, whenever possible, rivets were 'power driven'. This meant using a 'bull riveter', a large "C" frame with a rivet 'snap' or set on it's 'anvil' or fixed end, and a rivet snap driven by a hydraulic cylinder (or large air cylinder). These bull riveters were made with C frames having enough throat depth to be lowered onto a piece of plate and reach the rivets on seams on the further edge. Shipyards had these bull riveters hung on light jib cranes, positioned so they could be lowered and easily positioned to drive rivets on seams on the ship's hulls and framing. This was known as 'power driven' riveting. It still required a riveting gang to heat the rivets in a portable forge or some other heating device, and to get the heated rivets to where they were to be stuck into the holes. Hence, the heater, catcher, and sticker were still on the job. On the large ocean going ships, hand driving all the rivets in a ship's hull would have been something that would have stretched the building time out for quite a bit longer. There are only so many men that can be put into a given space at any one time. The power driven riveting was key. Power driven rivets were a more consistent thing than rivets driven by men holding a riveting gun. Using the riveting gun was 'hand driving', a misnomer as 'hand driving' conjures up images of crews swinging riveting hammers.
As late as the mid 1960's, riveted construction was still in use on major projects in the USA. I know the Verazzano-Narrows Bridge (from Brooklyn, NY to Staten Island, NY) was completed about 1964 or 65. The towers on that bridge were put together with shop-driven and field-driven riveting. The American Bridge division of US Steel was still riveting on main structural connections on that bridge in '64 or '65.
You ask an interesting question. "Bullfrog" was built during WWII if I remember the youtube correctly. That was a time of transition in shipbuilding from riveted to welded construction. Given the times and type of ship that "Bullfrog" was, my thinking is the ship was put together using rivets. Rivetting was a proven thing, it was in common use and the shipyards were set up for it, moreso than welding at that time.
Looking at a ship's hull, particularly after a few decades of slathered on paint along with rusting, it is sometimes hard to discern how the hull was put together. A riveted ship's hull does not have rivet heads projecting much beyond the exterior surfaces of the hull plates. The rivets are driven in countersunk holes, with a bit of a crowning just beyond the surface of the hull plates. This gives a 'fair' surface, with less drag in the water. Were the ship's hull riveted using rivets with a projecting head (such as 'acorn', 'button', or 'pan' heads), the thousands of rivet heads projecting from the hull would add tremendous drag.
The "Bullfrog" has what is known as a 'molded hull'. I.E., the plates are formed into curves in multiple axis. The seams where the plates meet are calked to seal them and make them watertight. Calking is done with an air rivetting gun with a blunt or radius'd end chisel steel in it. The calking chisel is driven into the edge of the plate overlaying or lapping the mating plate. The calking forms a groove in the edge of the overlaying plate and upsets the metal from that plate, forcing it into the underlying plate.
After decades at sea, a ship gets to resembling a hungry old horse, showing her ribs (frames). Years in heavy seas will cause the plates to be 'stove in' between the frames. The ship goes into the yards for repairs, and often, welding is used for the repairs. Plates may be cut out to access machinery inside the hull, or thinned or stove-in plates may be cut out and new plates welded in. Usually, on a riveted hull or boiler repair, the die is cast for continuing with riveting. It is easy enough to think in terms of welded repairs or alterations. However, welding sets up stresses, and tends to 'draw' as the welds cool. This can actually open up the calking on adjacent riveted seams. It is a bit of an art to determine when to continue with riveting vs welding. "Bullfrog" was a working ship. She was likely put into the yards and repaired and modified many times over her life. I am sure if a person were to get up close to her hull and take a good look, she'd have plenty of weld bead running on her plating and maybe some riveted plating patched in.
Even in this day and age, there is at least one shipyard up on the Great Lakes at Toledo, Ohio which still does riveted repairs. There are enough older hulls still in service on the Great Lakes for this shipyard (Ironhead, I think their name or nickname is) to keep doing riveting.
40 years ago or thereabouts, I worked on a job with an older gent who had been a shipyard boilermaker, and had worked on riveted hulls. We were working together on the construction of a new coal fired powerplant. This older gent told me how he'd been in a riveting gang and paid piece-rate, so much for each rivet driven. He told me he'd been driving what he called "Liverpool Rivets". He explained these were rivets driven into a countersunk hole. The other end of the rivet had a regular head (such as an 'acorn' or 'pan' head), and was stuck thru the holes from inside the hull so the plain shank stuck outside the hull. The heater, catcher, sticker and bucker (each of these guys has a specific job in a riveting gang) were inside the hull. The driver, which this gent happened to be, was on the outside of the hull. The gang on the inside would take an orange-hot rivet and stick it in the hole so the heated end of the shank stuck outside the hull. The driver would then "get on it" with his gun, using a 'rivet snap' which had a very shallow concavity. This fellow told me he made a lot of money driving those "Liverpool Rivets", claiming they had to be driven very fast because the hull plating would suck the heat away from the driven head way faster than with an exposed head. Being on piece rate, having to move fast to drive the Liverpool Rivets meant more rivets driven per shift and more money for the gang driving them.
Riveting is a method of construction that is not so bad as it sounds. It is definitely more labor intensive and makes for more difficulties in putting something together. However, when a rivet is properly driven, it 'upsets' to lock solidly in the rivet hole, and when the rivet cools, the contraction really clamps things together. This is known as 'bearing' in engineering. Riveted construction is quite an interesting subject in its own right. Having dealt with it many times on jobs over the years, I have some familiarity with it, and a LOT of respect for the crafts who built ships, boilers, tanks, and numerous building and bridge structures and so much else using riveting. When I see an old bridge or structure or some other riveted work being cut up for scrap, I get a momentary twinge, knowing how what it took to do that riveting. Not all rivets were driven by crews with hand-held riveting guns. In the shipyards, structural shops and boiler shops, whenever possible, rivets were 'power driven'. This meant using a 'bull riveter', a large "C" frame with a rivet 'snap' or set on it's 'anvil' or fixed end, and a rivet snap driven by a hydraulic cylinder (or large air cylinder). These bull riveters were made with C frames having enough throat depth to be lowered onto a piece of plate and reach the rivets on seams on the further edge. Shipyards had these bull riveters hung on light jib cranes, positioned so they could be lowered and easily positioned to drive rivets on seams on the ship's hulls and framing. This was known as 'power driven' riveting. It still required a riveting gang to heat the rivets in a portable forge or some other heating device, and to get the heated rivets to where they were to be stuck into the holes. Hence, the heater, catcher, and sticker were still on the job. On the large ocean going ships, hand driving all the rivets in a ship's hull would have been something that would have stretched the building time out for quite a bit longer. There are only so many men that can be put into a given space at any one time. The power driven riveting was key. Power driven rivets were a more consistent thing than rivets driven by men holding a riveting gun. Using the riveting gun was 'hand driving', a misnomer as 'hand driving' conjures up images of crews swinging riveting hammers.
As late as the mid 1960's, riveted construction was still in use on major projects in the USA. I know the Verazzano-Narrows Bridge (from Brooklyn, NY to Staten Island, NY) was completed about 1964 or 65. The towers on that bridge were put together with shop-driven and field-driven riveting. The American Bridge division of US Steel was still riveting on main structural connections on that bridge in '64 or '65.
Scottl
Diamond
- Joined
- Nov 3, 2013
- Location
- Eastern Massachusetts, USA
As the frog said, "Rivet, rivet, rivet".
The post was intended to be humorous.
The post was intended to be humorous.
