Circuit board goes pop? Whatabout those locomotives that transmit data to a central location?
. Unconfirmed reports are that it actually was CETC that had failed and needed rebooting. Center located at PHL 30th st station.
Another signal problem WASH - BAL delaying MARC. Note: Amtrak never lists these problems so the only part that gets reliable outage info.
If MARC issues these bulletins in a similar style to Metra, "signal problems" can cover a whole variety of sins.
Amtrak bulletin.
South end had another failure of signals. From MARC posting.
blue streak 1 South end had another failure of signals. From MARC posting. Feb 25 at 7:12 PM Trains on the Penn Line are experiencing a minor delay due to signal issues from New Carrollton to West Baltimore. Trains are operating at a restricted speed. We regret the inconvenience. EDIT -- unconfirmed report that tree across signal code or power lines ?
High winds for the past 48 hours in the Mid-Atlantic area, coupled with saturated ground from the snow melt from last months 2 foot plus blizzard and then the 2 plus inches of rain from the storm on the 24th. Perfect situation to blow trees over!
Never too old to have a happy childhood!
Once again another signal problem WASH - Perryville.
All northbound trains are currently experiencing a signal delay north of Odenton Station. Personnel are on sight working to correct the issue. Updates will continue as they become available.
And once again more CAT failures around WASH Union station
To
Run diesels and catanary isn't needed.
The PRR did a study back around 1960 or so considering that very thing. In the end they decided to keep the electrification. Maybe they shouldn't have, but I'm sure at the time it made sense.
Firelock76The PRR did a study back around 1960 or so considering that very thing. In the end they decided to keep the electrification
And that's where the E44s came from, and later the Metroliners instead of a glorified Turbotrain.
And then Conrail almost jumped the 'right way' in the early '80s with the dual-mode plan -- I still think that made sense to do at the time*, and in some contexts still might (especially with DC-link inverted motor control and practical wayside storage).
I am amazed we still have variable-tension cat at 25Hz and ancient infrastructure so many places on what was and is some of the fastest railroad in America.
Put constant-tension in across New Jersey and watch the fun start. (Although I will miss the amazing spark shows that the Silverliners put on with the old fixed cat during ice days in the wintertime!)
*that being, I believe, before Amtrak intentionally raised power charges in part to get freight off the Corridor. As I recall that's the prime factor that was 'stated' as leading to shutting down the Conrail electrifications, although it is also true that reducing the number of trains that can use an electrified Corridor rapidly makes the fixed overhead costs of electric traction uneconomical; that certainly applied to the Low Grade not just in terms of the catenary wirework but the track as well...
Meanwhile, Walk Bridge is apparently stuck open again...
Once again more CAT problems in the MARC area. This time there is no excuse as Amtrak has not cleared enough trees so a tree fouls the CAT on two tracks.
MARC Service Alert <alert@mtamarylandalerts.com> Due to trees in the catenary between Bowies State station and New Carrollton, trains in both directions may take a possible 10 to 15 mintue delay account of single tracking. OptOut: http://mtamaryland
Another failure on the MARC section of the NEC. It must be this area is the oldest part of the signal and CAT system of the PRR that has not been upgraded ? Anyone with more info ?
MARC Service Alert <alert@mtamarylandalerts.com> Due to signal and switch issue between Odenton and Bowie all Penn Line trains in both directions will operate 30-35 minutes late. Metro is honoring MARC Tickets OptOut: http://mtamarylandalerts.com/u.
Another failure today ( Friday )
MARC Service Alert <alert@mtamarylandalerts.com> Due to signal and switch issue between Bowie and Odenton. All MARC trains on the Penn Line in both directions will be be operating approximately 25-30 minutes late. Metro is honoring MAR Tickets. OptO
Another failure of reported switch but it may have been a signal problem ?
MARC Service Alert <alert@mtamarylandalerts.com> Train 401 has encountered a switch problem just south of Seabrook station. It will be necessary for the train to reverse back towards Bowie to change tracks. We expect 401 to operate approximately 20
BaltACD Run diesels and catanary isn't needed.
For me a train speeding through the countryside is a beautiful sight. Put it under a lot of wires, however, and it becomes ugliness personified.
What would be a maximum attainable speed today of a train like the Acela if it were pulled by a diesel electric locomotive?
What technical constraints would prevent the building of a diesel electric locomotive that could attain top speeds of 160 to 180 mph?
Rio Grande Valley, CFI,CFII
Catenary can be esthetically pleasing if designed right.
daveklepper Catenary can be esthetically pleasing if designed right.
Have to disagree on that. Some might be less ugly than others, but still ugly.
Mac
JPS1 BaltACD Run diesels and catanary isn't needed. For me a train speeding through the countryside is a beautiful sight. Put it under a lot of wires, however, and it becomes ugliness personified. What would be a maximum attainable speed today of a train like the Acela if it were pulled by a diesel electric locomotive? What technical constraints would prevent the building of a diesel electric locomotive that could attain top speeds of 160 to 180 mph?
Consider that a Siemens Sprinter electric weighs 215,000 lbs and developes 8600 hp (hourly rating), while an "EMD" F125 weighs 280,000 lbs and developes 4700 hp. It would take 2 diesels for the same hp. Do you really want half a million pounds running down the line at high speeds on a constant basis? Plus they would need extra weight for the dual power for NEC tunnels.
Another difference is that electric locomotives and train sets accelerate much more quickly than diesel-powered trains.
C&NW, CA&E, MILW, CGW and IC fan
Let me restate the questions with modifications.
My questions did not suggest restricting the trains to the NEC or taking down the existing poles and wires. Given the constraint of operating into and out of Manhattan, that probably is not going to happen.
Using existing technology, how fast could a diesel electric locomotive run pulling a train similar to the Acela? I had in mind power units at the front and back of the train, which is similar to the arrangement for the Acela.
If the development engineers - those that can think outside of the box - pushed the outside of the development envelope, what is the potential top speed attainable by a diesel electric locomotive.
Just a thought for the mechanical engineers (which I am not): what about using higher RPM diesels? Don't they produce higher HP per weight? As I recall, reduction gearing is used to drive the alternator in recent designs, but couldn't alternators be designed that could run at the higher RPM's? The higher RPM diesels supposedly would wear out more quickly, all else being equal, but would it make a difference that it would not be asked to drag the heavy loads that a freight engine would? ---Just thoughts unencumbered by detailed knowledge.
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"A stranger's just a friend you ain't met yet." --- Dave Gardner
The high speed diesel solution gets you a bit higher, to probably about 150 MPH.
Be aware of the problems that doomed the ICE TD sets, though, including high fuel consumption.
More likely would be a JetTrain type diesel+gas turbine solution.
Paul of CovingtonJust a thought for the mechanical engineers (which I am not): what about using higher RPM diesels?
The difficulty is in getting proper combustion with compression ignition (even assisted with pilot injection, promoters, and lasers) at the higher speed. Remember that there is a limited time (in degrees of crank arc translating to piston position) in which combustion has to go to completion (to produce the gas pressure that makes the engine horsepower) without quenching the combustion reaction early (this, in part, producing the nanoparticulates that are thought to be the most dangerous component in diesel exhaust).
In a locomotive engine that does not use urea but needs to adhere to Tier 4 final (and later) standards on NOx, there are limits on how much fuel you can burn even with high nominal boost and/or molecular sieve oxygen enrichment per 'combustion event', and this combined with the combustion time (and the need to avoid some of the detonation issues) will fix the output power of the engine. Since you're not concerned with mechanical transmission there is no reason to overspeed the engine at lower nominal efficiency to make higher speed.
Of course at higher speed other characteristics of a practical compression-ignition engine begin to cause problems or enhanced losses. The Russians built a high-speed diesel (TEP80-0002) that was able to reach 168mph, and I believe we have discussed the technology involved there in previous threads.
I have very little doubt, however, that for any road speeds much in excess of the 125mph or so of an HST, either a gas turbine with bottoming or a free-piston engine would be highly superior, the latter having very little limitation on the efficient production of 'just' the right amount of combustion gas for instantaneous horsepower, and the ability to run a positive-displacement expander for low speed or part load work.
Did Bombardier ever get that wacky second-generation JetTrain transmission to work properly? I suppose a little tech transfer from the B-mod Osprey might help if necessary.
NorthWest The high speed diesel solution gets you a bit higher, to probably about 150 MPH. Be aware of the problems that doomed the ICE TD sets, though, including high fuel consumption. More likely would be a JetTrain type diesel+gas turbine solution.
Keep in mind the top speed for ICE TDs is 125 mph (200 kmh). I believe they will all be retired by the end of the year. In 2014 I boarded a DSB (from Copenhagen) unit coupled to a ICE 3 (electric)in Hamburg, running to Berlin. Compared to the ICEs, they are quite noisy.
In case you aren't aware, MARC is replacing all of its electrics with Siemens Charger diesel-electric locomotives that are designed for 125 MPH.
MARC doesn't run their electrics that fast, today, anyway. There was an interview with an engineer who said that they like keep them around 119-121 MPH for passenger comfort reasons and the distance between stations since it's commuter rail.
MARC's Penn Line is still the highest-speed commuter rail line in the US and possibly the world.
You can design diesel or electric, diesel really being diesel-electric, for any top speed that is practical for topographpy and track. The top speed of a diesel prime mover is not directly related to the top speed of the train. The diesel train, whether mu or loco hauled or pusj-pull, will weigh a lot more than the electric, assuming the electric does not need ballasting to assure sufficient traction on starting on steep grades.
Once again the limitations of the variable tension CAT appear to have caused more problems
MARC Service Alert <alert@mtamarylandalerts.com> MARC Train 447 (5:50p dpt Balt) is operating 25-30 minutes behind schedule due to catenary issues. OptOut: http://mtamarylandalerts.com/u.aspx?336934
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