Thursday, December 22, 2011

Current Alignment Pittsburgh to Harrisburg Best Schedule

I was able in February of 2010 to have a member of the Talgo organization’s engineering staff review a copy of the Norfolk Southern’s track charts for the Pittsburgh to Harrisburg line.

Talgo is a firm with decades of experience with pendular suspended rail passenger equipment that makes it possible to operate rail passenger service at higher speeds than normal passenger equipment not using pendular suspension. Talgo has built equipment for American service. Currently, Talgo has provided equipment being used between  Seattle, OR to Vancouver, BC and Seattle, WA to Portland to Eugene, OR.

The Talgo staffer  made a calculation  westbound, mile for mile, of the speeds that could be maintianed on the existing alignment and super elevation of the outside rail on curves. It was assumed that signal spacing and road crossing protection would be adapted as required for the higher speeds. There appeared to be no problem with current signal spacing. Road grade crossings posed another problem. There are about 30 public crossings. Half the public crossings have active protection. Active protection means flashing signals and / or lowered crossing barriers. Also between the two cities are 40 private road crossings. Private crossings do not have active protection.

The distance between the Pittsburgh Amtrak station and the Harrisburg Amtrak station is 254 miles. However, the actual average mile is 5194.5 feet. This average length computation results from the fact that actual distances between mile posts range from 3947 feet to as long as 6451 feet. This lack of a uniform length per mile results from 157 years of engineering and maintenance history. So, the actual distance in 5280 foot miles is 249.9 miles.

An average potential speed for each mile was created. To do so, the speed leaving a prior mile with the maximum permitted in the next mile was compared. Track geometry and the capability of Talgo equipment were considered in context. If the new mile’s speed was higher than the entry speed a table developed by Talgo was used to determine how much available acceleration could be able to increase the speed in the time and distance available. A braking rate of 3 mph a second was assumed. ROugh approximations of where speed changes would begin and end were made. A weighted average of the entry and exit speeds were used to calculate the time needed to cover each mile assuming a 5194.5 foot mile.

Talgo could lessen the current 5 hour 30 minute schedule to 4 hours 10 minutes. The 4 hour 10 minute schedule retains the current schedule cushion of 34 minutes.

The rough estimate for Talgo equipment and the required maintenance facility would be about $40 million.

To upgrade the crossings for higher speed operations would be in the neighborhood of $15 million.

The Talgo staffer made some assumptions as to the probable fare for the Pittsburgh to HArrisburg line. Acela service on the North East corridor is the fastest service. Acela passengers pay a fare premium for the faster service. If that fare premium assumption were applied at 50% of what it is for Acela to Pittsburgh to Harrisburg line, a remarkable payback is possible.

Now, if there were a dedicated passenger track were the length of the Pittsburgh to Harrisburg line, the 34 minute schedule pad could be eliminated. A 3 hour 36 minute schedule is within the  realm of possibility with Talgo.

Google Maps computes a 3 hour 45 schedule time for the trip from the Pittsburgh Amtrak station to the Harrisburg Amtrak station using the Parkway East out of Pittsburgh to the Turnpike at Monroeville. After driving the Turnpike across the Alleghenies, Google Maps has the motorist leave the Turnpike at Harrisburg West exit using Route 581 into Harrisburg. The assumption made by Google Maps to declare a 3 hour 45 driving time is to assume satisfactory conditions for the time assumed.

The reality is that there will be a delay at the Squirrel Hill tunnel. There will be another delay at the Monroeville interchange. The unrelieved excitement of driving over the Alleghenies will often as not be accompanied with bad weather, truck congestion and the pleasure of driving over stretches of unaltered alignments from original construction in 1940. Admittedly the stretch past Donegal was rebuilt. The road was widened a few miles on either side of Somerset. The Allegheny Tunnel had an additional two lanes added with a new approach from the east that’s a tribute to highway engineering in the 1960‘s. That interchange at Bedford is the same alignment today as the day it was opened in 1940. Entering the road eastbound from Bedford now has the added excitement of enormous traffic volume bearing down upon a functionally obsolete, too short entry ramp. The road was rebuilt east of Bedford over Sidling Hill and Rays Hill but once over that, it is 1940 the whole way to Harrisburg West. It might be a better experience in a 1940 Packard.?!? East of Rays Hill to and  through Tuscarora, Kittatinny and Blue Mountain tunnels, the only difference is that the tunnels are now 4 lanes rather than th original 2 lanes. Otherwise, its 1940 for most of the trip to Harrisburg West interchange. Once off at Harrisburg West driving to Route 581, there is a strong likelihood for a delay.
The point of this is that a 3 hour 45 driving time is a possible time, not a probable time.

1 comment:

  1. any idea what the time savings, if any, would be east of harrisburg?