The engine is a "Single acting opposed piston engine" it had one combustion space between the main and exhaust piston and 2 injectors. Turbocharged - not suercharged. They operated on heavy fuel oil (typically 180cSt viscosity) when at sea and changed over to diesel fuel when entering port. The "double acting" engines had 3 pistons and 2 combustion spaces withing the same cylinder. If anyone is interested look it up. I was engineer for 1+ years on this type. Wonderful machines.
@tpvalley All 2 strokes that I sailed on had turbos. large 2 stroke marine engines use 3 methods (sometimes a combination). 1) roots type blower usually chain driven (old engines like H&W/B&W). 2) Under piston scavenging. The downward stroke of the underside of the piston is used to charge the cylinder. Reed type values are used (Sulzer RND) & 3) an electric blower (MAN) that cuts in at low speed. Today most engines are uniflow scavenged rather than loop scavenged.
if it has 2 combustion spaces it must be double acting, if single acting OP engine it has one combustion space between cylinders, if double acting it fires on both sides of one or both pistons- how can u have 3 pistons in one cylinder?????
@tpvalley Correct. A single acting OP has 1 combustion space between the main & exhaust piston. A double acting has 1 main piston with 1 exhaust piston above and 1 below = 2 combustion spaces. Suggest reading Marine Diesel Engine by CC Pounder. 3 in 1 cylinder. Simple. The main piston rod passes thru the lower exhaust piston.
I have seen harland and wolf , and B&W double acting engines, they used 2 pistons per cylinder just the piston rod sealed the combustion spaces on underside of pistons.
Under piston scavenging is rare I think; the sulzers i have seen used turbo and smaller scavenging pistons in paralel to main cylinders.
actually I stand corrected, the H&W engine has 2 big pistons and 1 or 2 smaller pistons controlling exhaust ports that R just bigger than piston rods.
It doesn't matter it is a beautiful engine, sadly not seen any longer. Sounds like a sowing machine and brings back many memories, although I was a Doxford man.
To put the matter straight this is a H&W 6-75VTF-150/50 single acting 2 stroke opposed piston engine. The bore is 750mm, the stroke of the main (bottom) piston is 1500mm and the exhaust (top) piston is 500mm. Unlike the Doxford Engine the exhaust piston is driven by eccentrics on the crankshaft. The fuel injection system is of the Bosch type wheras the Doxford has common rail. You could overhaul a unit in around 6 hours. I sailed on these engines in the 60/70ties ascadet up to Chief Engineer.
To clear up the arguments. Princess Danae was previously Port Melbourne. I can say this with some autthority as I sailed in the Port Melbourne as an Engineer Cadet in 1961 and (46 years later) in the Princess Danae as a passenger. . m/v Port Melbourne was built in 1955 at Harland & Wolff Belfast and has Burmeister & Wain (Denmark) engines built by H&W under license from B&W. Her original engines are still running after 55 years - a tribute to those who built, operated and maintained them.
I sailed on the Rockhampton Star in the late 70's which had an 8 Cylinder Burmeister & Wain opposed piston engine built by Harland and Wolff in Belfast in 1957
The earlier B & W engines (between the wars) had three pistons so were double acting opposed piston.. there is a model of one in the Science Museum in London
As for low noise on the Doxford engines is that most did not have turbochargers but scavenge pistons instead
I work for a non destrucive testing company and I am sure it was the Rockhampton Star where I found thread cracks on an exhaust piston tie rod. The Superintendent let it do one more round trip - no spares available- and they pulled it next time in London. IThe rod was removed and put in KGV drydocks workshops and how it had lasted I do not know. Would have been interesting if it had broken at sea.
FIAT has also build 2 or 3 of this engine one is instald in an litle cruiseship ex Hurtigruten called Harald Jharl this ship was build in Norway in 1958 and was taking out of servise in 1997,this is an wery nice engine and its run at 150rpm and its has 3500 horsepower
Should have mentioned that 'Princess Danae' was built as 'Port Sydney' by Swan Hunter's, Wallsend on Tyne hence she WAS propelled by twin Doxford engines, she was not the 'Port Melbourne' which might account for the fact the engines shown are B&W type and possibly built by Harland & Wolff
'Princess Daphne' was built as MV 'Port Sydney' not 'Port Melbourne' as mentioned. Good to see there still a few people who recognise that the engines shown are not Doxfords, but B&W type, still nice bit of film!!
I served on Blue Star Port Lines, most of their motor ship had the same H&W direct drive diesels, nice , but a lot of work to change a piston, looks very impressive when running full ahead !!!
Crossed the pond a few times with H&W engines during the 70s. They are opposed piston on a single cranshaft, If I recall correctly the top piston is the exhaust piston. As it rises it exposes exhaust ports, the lower piston exposes the inlet ports, uses a Roots mechanical Blower to boost inlet pressure. I am sure they are 2 stroke with heated heavy oil fuel injection. Great times in those days travelling the east coast of S. America and an education!!!
I am pretty sure that this is a Harland & Wolf opposed piston engine. It is not double acting since this would have to have 2 combustion spaces. This one has 1. Quite complicated enough. I sailed on one just like it in the 70's and compared the video to some photos that I have. These were wonderful engines to operate and maintain. It took a couple of days to overhaul a unit (piston) versus a few hours on a modern slow speed diesel.
I never claimed it to be a Doxford engine, but a Doxford type engine in the sense that the top pistons of an opposed piston engine are not connected to a second crankshaft but to the main crankshaft through long rods. Main exterior differences between this engine and a "true" Doxford are the presence of 4 rods per cylinder instead of two and the absence of the guiding rails for the top cylinder.
I'm trying to get this all straight .
The Danae has Burneister & Wain designed engines built by Harlan & Wolff
The Daphne has Doxford built engines ?
At least some other video's show the lower levels of the Daphne engine room with Doxford emblems on the machinery ?
Am I correct with this ?
At any rate they both are very neat ships and the vedeo's are great !
clifftech1 1 month ago
The engine is a "Single acting opposed piston engine" it had one combustion space between the main and exhaust piston and 2 injectors. Turbocharged - not suercharged. They operated on heavy fuel oil (typically 180cSt viscosity) when at sea and changed over to diesel fuel when entering port. The "double acting" engines had 3 pistons and 2 combustion spaces withing the same cylinder. If anyone is interested look it up. I was engineer for 1+ years on this type. Wonderful machines.
bayoulimey 3 months ago
@bayoulimey
so how does it scavenge on start up when turbo/s are not turning?
I have seen some large 2 strokes with superchargers or turbo's and extra scavenge pistons, is that the case here?
tpvalley 1 month ago
@tpvalley All 2 strokes that I sailed on had turbos. large 2 stroke marine engines use 3 methods (sometimes a combination). 1) roots type blower usually chain driven (old engines like H&W/B&W). 2) Under piston scavenging. The downward stroke of the underside of the piston is used to charge the cylinder. Reed type values are used (Sulzer RND) & 3) an electric blower (MAN) that cuts in at low speed. Today most engines are uniflow scavenged rather than loop scavenged.
bayoulimey 1 month ago
@bayoulimey
if it has 2 combustion spaces it must be double acting, if single acting OP engine it has one combustion space between cylinders, if double acting it fires on both sides of one or both pistons- how can u have 3 pistons in one cylinder?????
tpvalley 1 month ago
@tpvalley Correct. A single acting OP has 1 combustion space between the main & exhaust piston. A double acting has 1 main piston with 1 exhaust piston above and 1 below = 2 combustion spaces. Suggest reading Marine Diesel Engine by CC Pounder. 3 in 1 cylinder. Simple. The main piston rod passes thru the lower exhaust piston.
bayoulimey 1 month ago
@bayoulimey
I have seen harland and wolf , and B&W double acting engines, they used 2 pistons per cylinder just the piston rod sealed the combustion spaces on underside of pistons.
Under piston scavenging is rare I think; the sulzers i have seen used turbo and smaller scavenging pistons in paralel to main cylinders.
tpvalley 1 month ago
@bayoulimey
actually I stand corrected, the H&W engine has 2 big pistons and 1 or 2 smaller pistons controlling exhaust ports that R just bigger than piston rods.
tpvalley 1 month ago
@bayoulimey
correction one combustion space between pistons.
tpvalley 1 month ago
L.S
I noticed that the name of this video "DOXFORD TYPE ENGINE ,gave a lot of confussion instead of HARLAND & WOLFF B&W Opposed Piston Engine
Alfons
averheijden 3 months ago
Eccentrics were used to shorten the crankshaft as they form part of the adjacent crankpin web.
jeremymeadows100 6 months ago
Two many side rods for me, love the telescopics for the top piston cooling, it took Doxfords a while to get there. P types were the first I think?
Snikers777105 9 months ago
It doesn't matter it is a beautiful engine, sadly not seen any longer. Sounds like a sowing machine and brings back many memories, although I was a Doxford man.
Snikers777105 9 months ago
Does anyone else here feel like they want to hop on top of that thing and go for a ride?
Al828282 9 months ago
To put the matter straight this is a H&W 6-75VTF-150/50 single acting 2 stroke opposed piston engine. The bore is 750mm, the stroke of the main (bottom) piston is 1500mm and the exhaust (top) piston is 500mm. Unlike the Doxford Engine the exhaust piston is driven by eccentrics on the crankshaft. The fuel injection system is of the Bosch type wheras the Doxford has common rail. You could overhaul a unit in around 6 hours. I sailed on these engines in the 60/70ties ascadet up to Chief Engineer.
jeremymeadows100 10 months ago
@jeremymeadows100 "the exhaust piston is driven by eccentrics on the crankshaft" Do you k now why they went that route?
partsproduction 7 months ago
GREAT VIDEO I USED TO BE A JUNIOR ENGINEER WITH HOULDER BROS OF LONDON MY FIRST SHIP WAS MV SHAFTESBURY A DOXFORD HAVE LOVED THEM EVER SINCE
lmogden1 10 months ago
0:24 Manila gasket :D
joffeloff 1 year ago
Thanks gquadrado for posting this, Takes me back to good memories.
tidy872 1 year ago
Comment removed
tidy872 1 year ago
I'm wandering what are the dimensions of this engine, namely the height. Is this engine propelling a ship?
gr, Tom
tom89whoop 1 year ago
To clear up the arguments. Princess Danae was previously Port Melbourne. I can say this with some autthority as I sailed in the Port Melbourne as an Engineer Cadet in 1961 and (46 years later) in the Princess Danae as a passenger. . m/v Port Melbourne was built in 1955 at Harland & Wolff Belfast and has Burmeister & Wain (Denmark) engines built by H&W under license from B&W. Her original engines are still running after 55 years - a tribute to those who built, operated and maintained them.
yorkham100 1 year ago
This is not a Doxford Engine it is a B&W engine
asphalion123 1 year ago
I sailed on the Rockhampton Star in the late 70's which had an 8 Cylinder Burmeister & Wain opposed piston engine built by Harland and Wolff in Belfast in 1957
The earlier B & W engines (between the wars) had three pistons so were double acting opposed piston.. there is a model of one in the Science Museum in London
As for low noise on the Doxford engines is that most did not have turbochargers but scavenge pistons instead
lucky4sum 1 year ago
bohol2
I work for a non destrucive testing company and I am sure it was the Rockhampton Star where I found thread cracks on an exhaust piston tie rod. The Superintendent let it do one more round trip - no spares available- and they pulled it next time in London. IThe rod was removed and put in KGV drydocks workshops and how it had lasted I do not know. Would have been interesting if it had broken at sea.
bohol1 1 year ago
I was a sailor in the engines, never on an engine like this or similar, but on huge MAN cross head 2 stroke crude oil diesels.
Can anybody explain to me why these Doxford like engines seem to work more or less without any noise compared to a cross head 2 stroke diesel??
XELA2T 1 year ago
Reminds me of my time on the Adelaide Star & Ulster Star in '68 & '69. Nice video.
dckrynr 2 years ago
This is not a Doxford type of engine ? it's an double action engine, is it not ?
johnsenkenn 2 years ago
FIAT has also build 2 or 3 of this engine one is instald in an litle cruiseship ex Hurtigruten called Harald Jharl this ship was build in Norway in 1958 and was taking out of servise in 1997,this is an wery nice engine and its run at 150rpm and its has 3500 horsepower
jensenmekk 2 years ago
nice one, i worked on the MV, Brittish TRust, one of the 16,000 ton bird class, 1974, she had an oppossed piston doxfors simmilar to this one,
cool video.
thom.
fuelban 2 years ago
Should have mentioned that 'Princess Danae' was built as 'Port Sydney' by Swan Hunter's, Wallsend on Tyne hence she WAS propelled by twin Doxford engines, she was not the 'Port Melbourne' which might account for the fact the engines shown are B&W type and possibly built by Harland & Wolff
Hereman7 2 years ago
'Princess Daphne' was built as MV 'Port Sydney' not 'Port Melbourne' as mentioned. Good to see there still a few people who recognise that the engines shown are not Doxfords, but B&W type, still nice bit of film!!
Hereman7 2 years ago
I served on Blue Star Port Lines, most of their motor ship had the same H&W direct drive diesels, nice , but a lot of work to change a piston, looks very impressive when running full ahead !!!
JohnDT60 2 years ago
Crossed the pond a few times with H&W engines during the 70s. They are opposed piston on a single cranshaft, If I recall correctly the top piston is the exhaust piston. As it rises it exposes exhaust ports, the lower piston exposes the inlet ports, uses a Roots mechanical Blower to boost inlet pressure. I am sure they are 2 stroke with heated heavy oil fuel injection. Great times in those days travelling the east coast of S. America and an education!!!
microcrusader 3 years ago
I lived a few hundred yards from where these engines were made
great video thanks for this
airstreamed 3 years ago
I am pretty sure that this is a Harland & Wolf opposed piston engine. It is not double acting since this would have to have 2 combustion spaces. This one has 1. Quite complicated enough. I sailed on one just like it in the 70's and compared the video to some photos that I have. These were wonderful engines to operate and maintain. It took a couple of days to overhaul a unit (piston) versus a few hours on a modern slow speed diesel.
bayoulimey 3 years ago
This is not a DOXFORD Engine, but most pobably a Harland & Wolf double acting "B&W" Engine
Regards
Alfons
averheijden 3 years ago
I never claimed it to be a Doxford engine, but a Doxford type engine in the sense that the top pistons of an opposed piston engine are not connected to a second crankshaft but to the main crankshaft through long rods. Main exterior differences between this engine and a "true" Doxford are the presence of 4 rods per cylinder instead of two and the absence of the guiding rails for the top cylinder.
Regards
Gonçalo
gquadrado 3 years ago 2
This engine is also double acting, ie each piston pushes and pulls with combustion space each side of each piston!
Theres a website with the cross section.
tpvalley 2 years ago
I suppose this is a one stroke engine!
it fires every stroke up and down!
tpvalley 2 years ago
@tpvalley Who knows the battle between Doxford and Harland & Wollf concerning patent problems?
Alfons
averheijden 1 month ago