MikeF90To tie this topic back to something railroad related, I can only speculate about the noise impact of running many turboshaft powered trains if it became economically feasible. Those early jet engines were Loud; the loudest one I've heard by far was on a ROKAF C-123K - ear bleed noisy!
Fixed that for you (not that you didn't know already!)
The engines in the UA Turbotrain were PT-6s. Those made a recognizable 'jet noise' but not at particularly high decibels, or with the kind of widespread diffusion of noise that an airborne engine driving a large propeller would produce. If there had been a problem with noise in service, I'd expect better exhaust silencing in the frequency bands of concern would have been used.
I can't speak to the French engines (Turbomeca?) although they couldn't have been as bad as the little dental drills used in turbojet aircraft like the Magister. That nasty shriek, even at low volume, would cure anyone from wanting increased passenger service.
The UP gas-turbine engines are NOT representative of what passenger turboshaft-powered trains would produce!
Externally the loudest jets were the Viscount ( turbo prop & and Caravelle straight jet ) Know flight engineer who would go inside of concourse at ORD whenever UAL operated one into concourse "D". He could stand Electras because they had two speed engines running on low speed when taxiing. ~10,000 and 13200 RPMs
The noise along the prop plane of an Electra usually happend when scynorizing system did not operate properly. Same for Convair CV-580s ( reengined Convair CV-440 )
For reasons unknown when starting cold 3 bladed reciprocating engines such as connie the standard was to count about 15 blades before applying fuel. A real art to starting them as a 2 handed job to control mixture, starer safety switch, ignition booster, throttle, and primer so not to backfire engines. Always knew who the newbies were. By the way some long distance recips carried copious amounts of engine oil. ie CV-440s ( short haul ) carried 30 Gallons don't know what others carried.
RMEThe Electra had paddle-blade propellers and made the typical noise associated with those, exacerbated by high turbine power. All I might need to say is 'powerful enough to induce whirl-mode wing failure'... Most of the noise inside the cabin was for seats forward of the wing. If I recall correctly the noise was relatively rich in discordant low frequencies.
Fortunately Lockheed learned from the early Electra disasters and later models along with the P-3 were quite rugged. Interesting that the latter didn't get the scimitar propeller as its C-130 cousin did. But I digress.
I flew in a Convair turboprop several times and did not find it that noisy, perhaps because the trips were short. In the jet age flying in a turboprop can be a novelty.
To tie this topic back to something railroad related, I can only speculate about the noise impact of running many turbojet powered trains if it became economically feasible. Those early jet engines were Loud; the loudest one I've heard by far was on a ROKAF C-123K - ear bleed noisy!
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RME Most of the noise inside the cabin was for seats forward of the wing. If I recall correctly the noise was relatively rich in discordant low frequencies.
Most of the noise inside the cabin was for seats forward of the wing. If I recall correctly the noise was relatively rich in discordant low frequencies.
The Airbus A320 treats the first-class cabin and flight deck to "propeller noise" from the turbofans that project forward from the wing. In a turbofan engine at takeoff or climb power, it is called "buzzsaw noise" because that is what it sounds like. We coach-class discount-fare Boarding Zone 3 peons in the back of the plane get a quieter ride.
Part of why I asked that question was that there was acoustics research interest in the prop-fan (Pratt and Whitney-Hamilton Standard) and unducted fan (General Electric) proposals for jet-engine speeds with propeller fuel economy. The question was whether such planes could be made quiet enough for acceptance by airline passengers accustomed to jets. In the research papers presented at the Acoustical Society of America, there was reference to the Viscount, a British turboprop, which was supposed to be remarkably quiet for a propeller aircraft on account of a serious effort to take acoustics into account in its design.
I also had occasion in the very late 1970s to visit an acoustic test chamber facility in connection with work that I was doing, and I asked the operators about sheet posted on their bulletin board describing the prop-fan -- this facility may have done some tests in support of that program. I was told, "A jet is Mach .86 but the airlines are slowing down to Mach .75 for fuel economy reasons, the prop-fan in Mach .7. Heck, a Lockheed Electra is Mach .6, instead of the prop-fan, why not just fly a bit slower and then you can use a Lockheed Electra."
Maybe a Lockheed Electra is just awfully noisy and unacceptable to many passengers? My recollection of the Convair 330 conversions to twin turboprops is the noise and vibration was so strong you think would lose dental fillings, and that one pilot told me an Electra was "a Convair on each wing." Is that why over 30 years later the prop-fan idea hasn't gone anywhere?
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
flew on all these plains. Softest to loudest: Convair, Electra, DC-7, DC-6, Constilation. All except Convair noisier than a jet inside, but not outside.
Jets, noisiest to loudest: 747, DC-9, DC-8, 727, 707. 707 and Convair about equal. Earliest 707s a bit noisie.
schlimm Paul Milenkovic I asked an airline pilot who was in a position to know something about the L-188 you have pictured, known as the Lockheed Electra. "I have ridden on a twin-engine turboprop Convair, and that was loud -- is the Electra loud (in the cabin from prop noise)." "Is the Electra loud?" was the answer posed as a stupid question, "you have a twin-engine Convair . . . on each wing!" If he was an Eastern pilot, he must be pretty old now, or else a very young pilot when he flew Electras. Eastern last flew one in 1977. Perhaps he flew for some freight line later? My memory of flying twice on American to DC in the mid-60s was that it was very quiet compared to piston-engined planes.
Paul Milenkovic I asked an airline pilot who was in a position to know something about the L-188 you have pictured, known as the Lockheed Electra. "I have ridden on a twin-engine turboprop Convair, and that was loud -- is the Electra loud (in the cabin from prop noise)." "Is the Electra loud?" was the answer posed as a stupid question, "you have a twin-engine Convair . . . on each wing!"
If he was an Eastern pilot, he must be pretty old now, or else a very young pilot when he flew Electras. Eastern last flew one in 1977. Perhaps he flew for some freight line later? My memory of flying twice on American to DC in the mid-60s was that it was very quiet compared to piston-engined planes.
This was in 1986 -- I am older than many think.
The Electra had paddle-blade propellers and made the typical noise associated with those, exacerbated by high turbine power. All I might need to say is 'powerful enough to induce whirl-mode wing failure'...
I never asked anyone who might have flown Electras in passenger service whether they were noisy from the cockpit, but have read plenty of accounts that said they were (relative to other contemporary aircraft in the same general expected performance range).
Paul MilenkovicI asked an airline pilot who was in a position to know something about the L-188 you have pictured, known as the Lockheed Electra. "I have ridden on a twin-engine turboprop Convair, and that was loud -- is the Electra loud (in the cabin from prop noise)." "Is the Electra loud?" was the answer posed as a stupid question, "you have a twin-engine Convair . . . on each wing!"
C&NW, CA&E, MILW, CGW and IC fan
Eastern's sole 737-700 was the plane that overran the runway at LGA on the 27th, though its logos were blanked by the campaign chartering it. Rumor is they appear to have floated and touched down with only 2300 feet of runway remaining.
The speed brake actuators were MELed but we'll see if lack of autospoilers had anything to do with the end result.
They also have 4 737-800s and several planes on order but appear to be flying charters only at this time.
I was in the "Jet Room", to outward appearances a greasy-spoon diner at the local general-aviation terminal with great homemade pies and a lot of aviation lore discussed at the lunch counter.
I asked an airline pilot who was in a position to know something about the L-188 you have pictured, known as the Lockheed Electra.
"I have ridden on a twin-engine turboprop Convair, and that was loud -- is the Electra loud (in the cabin from prop noise)." "Is the Electra loud?" was the answer posed as a stupid question, "you have a twin-engine Convair . . . on each wing!"
CMStPnPIt's a PR photo of the turboprop, they are using modern jets.....
Yes, they should have had a L-188 in there somewhere:
Seems like just yesterday they flew the last propeller Air Shuttle with them.
That in turn made me think of the billboard in some nasty part of Philadelphia, visible from the Metroliner windows, that said "You'd Be There By Now On The Air Shuttle". I did NOT appreciate that.
Whisperjet
The challenge was caused by the T-tail. I learned much later that if the plane is about to stall, the elevators are useless for lowering the nose because they are in the disturbed air in the wake of the wings (or something like that).
My first airplane flight was on Eastern, Feb. 1966; from O'hare to Jacksonville. Flew a 727. Wonderful trip. One thing, you knew you were going up in the air after takeoff in those. I guess they were challenging to land.
Here is bit more awesome:
https://www.youtube.com/watch?v=v3MBmS3APP0
Was a crew chief on a Marine Corps R5D. Went through many engine starts like this. And some that did not go so well.
Rio Grande Valley, CFI,CFII
So they didn't have "waste gates" to dump any excess pressure ahead of the turbines? What about crew training?
OK, OK, in a military and especially a combat environment the pilot may make rapid power changes. The same applies in civilian operations, especially an emergency such as being caught in a downdraft.
But other than that, there are few aviation engines apart from a primary trainer where you can do whatever you want with the throttle, pitch, and mixture controls. It is just like on a steam locomotive, you have to learn the limitations of the machinery and operate the controls accordingly.
The PRT was supposed to recover unused energy in the exhaust gasses and pass it on to the main crankshaft. Like most turbines, it operated best at a steady RPM and output, at cruise, at altitude.
Problems arose with rapid changes in throttle settings. A too-quick application of power would result in a pressure buildup in the exhaust manifolds, since the fans wouldn't speed up until they responded to the greater volume of exhaust gas. Thus backfiring into the intakes and a few seconds of very rough operation. At the opposite, if the engine was powered down the still-speeding turbines would suck cold fuel-air mix into the exhaust manifold, sometimes resulting in a belch of flame and fan blades out the exhaust, or, more frequently, micro-cracks in the cylinder head around the exhaust port. The C-119 used R3350-PRT engines. Later they were converted to gunships. I can't think of a worse environment for a system averse to abrupt throttle movement.
Quick spotter trick. The R3350 was a two-row 18-cylinder engine - short and relatively fat cowling ahead of the cowl flaps. The R4360 was a 4-row, 28 cylinder engine, slimmer and almost twice as long as the R3350. Compare photos of B-29 and B/KB-50 aircraft.
Chuck (Worked on both, didn't love either)
R-4360's? For the DC-7 try R-3350 https://en.wikipedia.org/wiki/Douglas_DC-7 .
And how can the power recovery turbine (PRT) be "swallowed into the cylinders"? Each PRT was driven by the exhaust gas from a group of cylinders, and it was connected mechanically to the propeller shaft through, yes, an automobile automatic transmission torque converter, hence the name power recovery turbine.
Eastern had both the L 1049 and mostly L 1049 Cs. Eastern got 76, operated from 1951-1968. Eastern operated 49 DC-7Bs. They leased 13 DC-6s and DC-6Bs. The OP's picture is a 7, as they had 4-bladed props, while 6's had, at least originally, 3-bladed props.
Eastern (EAL) operated DC-6s, DC-7s, and Constellations L1049 (g?)s in the earl 1960s.
EAL first got rid of the DC-7s and kept the -6s and connies. It all came down to the engines. Although connies and -7s both had R-4360s engine the DC-7 had a much higher engine faiure rate. Old timers claimed it was due to inadequate cooling on the -7s. If you study the cowlings you can see that the -7s are much more streamlined and have been told cowl flaps were inadequate. The PRT ( a type of tubro charger ) often failed on -7s being swallowed into the cylinders.
So EAL started operating the shuttle with -6s and Connies. The -6s had R-2800s which were also on CV-440s. -6s were retired next with Connies staying on shuttle. Since it was so reliable EAL kept one Connie for ferrying jet engines around its system until the airline acquired B-727-QC passenger/freighters.
Another factor for the Connies was they took off at a much lower gross weight and mostly did not need to use the PRTs for takeoff power. Connies also had a sophisticated engine analysis system that could predict certain failures. Remember the USAF and weather service kept them in hurricane hunter service for a long time.
TWA was still operating L-1049Hs in transatlantic service while Pan Am had started using B-707s quickly because it was in a rush to get rid of its DC-7s.
Delta also got rid of its -7s first and kept three DC-6s that were converted into freighters. It retired the -6s when it acquired three L-100s ( civilian version of C-130 ).
Firelock76 "...China Clipper calling Alameda...China Clipper calling Alameda..."
"...China Clipper calling Alameda...China Clipper calling Alameda..."
I can't hear the name Alameda without thinking about that movie.
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
What I don't have is my "junior pilot" badge from Pan Am as well as the booties we had to wear when we toured a 707 on a class trip to Idlewild Airport in 1962. The girls were all junior stewardesses. I still have the coloring book from Pan Am that everyone was given. I did a nice job of coloring the Pan-American Grace (Panagra as I recall) DC-6? in the proper gold hue if I say so myself!
Eastern has indeed "risen from the ashes"; I saw a Boeing 737-800 in Eastern livery at BWI. I think it's either a charter airline or one with very limited destinations. I believe I still have my long-expired Ionosphere Club membership card somewhere.
“Things of quality have no fear of time.”
CMStPnP It's a PR photo of the turboprop, they are using modern jets..... http://easternairlines.aero/
It's a PR photo of the turboprop, they are using modern jets.....
http://easternairlines.aero/
The PR picture shows a Douglas plane, a DC 7B, in an older paint scheme. The engines were not turboprops, rather radial reciprocating engines, from Wright.
I rather like the idea of Eastern rising from the ashes.
I'm somewhat less thrilled with the idea of piston power. Having worked on aircraft with up to 28 cylinders per engine I know that they are far more complex and failure prone than anything with a large exhaust pipe and a gutful of discs and blades. Want proof? Just look at the mandatory overhaul intervals, pistons versus turbines.
Chuck (retired USAF maintenance technician)
schlimm CMStPnP Well first this is a link to the History Page which is interesting to read given we are repeatedly told the airline industry has always been self sufficient.....yeah right. Anyway, I remember flying them in 1972 on their new Bahamas route. Lockhead 1011 from Chicago to Miami as I recall and a 727 from Miami to Nassau. http://easternairlines.aero/about/history Flew on an Eastern Super Constellation LGA-Bermuda in 1956 just after they took over Colonial.
CMStPnP Well first this is a link to the History Page which is interesting to read given we are repeatedly told the airline industry has always been self sufficient.....yeah right. Anyway, I remember flying them in 1972 on their new Bahamas route. Lockhead 1011 from Chicago to Miami as I recall and a 727 from Miami to Nassau. http://easternairlines.aero/about/history
Well first this is a link to the History Page which is interesting to read given we are repeatedly told the airline industry has always been self sufficient.....yeah right.
Anyway, I remember flying them in 1972 on their new Bahamas route. Lockhead 1011 from Chicago to Miami as I recall and a 727 from Miami to Nassau.
http://easternairlines.aero/about/history
Flew on an Eastern Super Constellation LGA-Bermuda in 1956 just after they took over Colonial.
Current registration - N6937C After completed as L1049H N5400V, stored at Lockheed Aircraft, Burbank, CA due to cancelled order, til sold. Info and Photo @ http://www.conniesurvivors.com/N6937C.htm
Pat Ryan and Terry Lee were on thier way to the Orient and many adventures with the Dragon Lady.
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