EBay is currently offering a F-M OP.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7592159247
OP’s are still around as stationary and marine engines, where having to remove that upper crankshaft for maintenance is less of a hassle than in a railroad shop.
What is/was the perceived advantage of this design that compensates for the extra weight of having 2 crankshafts and the gears to connect them together?
It’s based on Newton’s Third Law of Motion. For every action there is ann equal and opposite reaction.
In a single piston engine the reaction is acting on the cylinder head, which is stationary. In an OP engine the reaction force drives another piston so you get more power.
Proof that you can find anything on eBay. I never saw an FM engine in operation, I understand they had a rather unique sound. From what I have read, the maintenance on these in a railroad sense far outweighed any advantage of power they had. Not really a railroad engine, but good in other circumstances. I personally am intrigued by the english “Deltic” engines, which have cylinders everywhere at all angles, anyone ever hear of those?
Those are interesting engines, with the one crankshaft counter revolving opposite the other two to offset the out of phase piston movement?
Cut away:
Demonstration of piston cycle:
I was wondering what maintenance was like for these engines?
Looks to me the best bet would be to simply keep spares rebuilt on hand, and swap out the entire mill for any serious repair work
whoa… i think i’ll just stick with my big block chevy’s.
Near their end in railroad operations, the FM’s sprayed oil all over the place.
I suspect the may have been very good engines in Stationary and Marine operations where RPM’s for the most part stayed steady for hours and hours if not days and days.
Railroad operations are far from steady state operations for prime movers and I don’t believe the FM was really up to the stresses.
Yes, a Deltic at full throttle was an incredible sound. Each engine had three banks of 6 cylinders making a total of 18 cylinders and 36 pistons per engine, each locomotive had 2 engines, so you had a total of 36 cylinders and 72 pistons in each loco. I have been through the engine compartment of one of these locos when it was flat out at 100 mph on the east coast mainline, my ears were ringing for several days afterwards! From the trackside they can sound a bit like a turbine. The total horsepower was 3300, quite a high figure for the 1960s. When first introduced the engine maintainance was done by English Electric but was later done in house at Doncaster Locomotive Works (always known as “The Plant”) A stock of rebuilt engines was always kept on hand so a loco could be sent into The Plant with engine problems and be back out in service the next day. The engines were originally developed by Napier for the Royal Navy to power Motor Torpedo Boats where a high power to weight ratio diesel engine was required to replace the Packard Merlin petrol (gasolene) engines then in use. Prior to World War 2, Napier had aquired the license to build opposed piston diesel engines from Junkers in Germany who utilised OP diesel engines in some of their bombers during the war.
Malc.
That Deltic design is awesome…!! Never have seen anything near like it…Never even heard of anything similar before…! Of course did know about the F M units and heard them run, etc…On the Deltic units, I assume the three cranks were gear connected at the opposite end {in the illustration drawing above}…and that animation is great too…
Such an array of moving parts to care for and keep in shape, and proper oiling…Just can’t imagine anyone building something like that…I wonder how long it would run before it’s many parts would start to cause some problems…and really how much of an horsepower advantage did it really have for a similar basic size unit to fit in an engine compartment…It sure is wild to look at the drawing and ponder it in motion…!
That engine is very unique. [^]
I bet maintainance was a nightmare though. [:0] [B)] [8]
Did they put any into the English PT boats?
You must agree it is an interesting engine to say the least.
I wonder how available parts are for it? [?] [?] [?]
This animation is a little “over the top” but includes a sound track of the deltic engine dubbed in the back ground, or so the author claims anyway
the file size is massive, so dialup web users are not likely to enjoy this at all.
If the animation fails to run when you browse the link, then select “file/save as” from yout browsers menu and save it as a local file on you machine and run it that way
]
That engine is very unique. [^]
I bet maintainance was a nightmare though. [:0] [B)] [8]
Did they put any into the English PT boats?
You must agree it is an interesting engine to say the least.
They were fitted in the Brave class motor torpedo boats and I think some larger ships, frigates, destroyers and cruisers used them to power auxiliaries (generators, pumps etc.).
The royal navy originally wanted a diesel powered MTB to eliminate the fire risk on the earlier boats with their triple Packard Merlins, each of which burned 4 gallons a minute of petrol (Gasolene)when at full power, that is Imperial gallons, not your small US gallons. These small wooden boats therefore had to carry vast quantities of highly flammable fuel, not a comfortable place to be when under attack.
When the Royal navy finally stopped using Deltic engines, British Rail wisely snapped up their entire stock of spares at a bargain price.
I was once told that the New York Fire Dept. had a truck mounted pump powered by a Deltic engine because it was light enough to be easily carried on a truck and powerful enough to pump water up to the top of any New York skyscraper. Can anyone confirm whether this story is true or not?
Malc.
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AntiGates…I’ll be satisfied with just the layout of animation you presented on your post as I am on dial-up…With that and the drawing of the cutaway is just great to see and easy to understand. Having been around automotive stuff all my life it is something I can appreciate…even though the concept was not automotive. It reminds me of the comparable compexity of radial airplane engines w / three banks of cylinders, etc…Just happen to appreciate such wild engineered stuff…
That cutaway animation of the Deltic was really cool.Were any Deltics preserved? Are any Deltics in operation today?The sound must have been awesome.I have heard FM diesels in operation,but have never been on the other side of the pond to experience a Deltic.
There’s a common interest we both share. My curiousity is how they kept enough oil on the top two crankshafts to keep the main bearings both lubed as well as cool, without fouling the cylinders below them…
There are 6 surviving Deltics, not including the original EE Prototype (which looked very similar to the production locos but was not identical). http://www.thedps.co.uk/ have three and information on the others. All are either running or undergoing restoration apart from the prototype (named Deltic). This loco had a different design of power unit mounting to the production examples and rebuilding the original power units would be very costly - the NRM would not allow it to be re-engined with the later type. Apparently it’s also missing a lot of wiring though it’s been cosmetically restored.
The FDNY had a Super Pumper system that used the Napier Deltic marine engine to power the fire pump.This was used with a Super Tender with a giant water cannon,and it could put out 8800 GPM.It could literally knock down walls.I believe both units survive in private hands.