02 January 2016

Special Provision SP01040

Buried deep in the fine print of Caltrain's electrification Request For Proposals, Volume 3, Part C, Paragraph 1.04, you will encounter Special Provision SP01040.  It defines where and when the electrification contractor will be allowed access to Caltrain's tracks to perform the work of re-signaling and electrifying the railroad.  These are known as "work windows" and are tabulated at right, as extracted from the RFP.

What follows is an analysis of the far-reaching cost and schedule implications of Special Provision SP01040.

Temporal Windows

Special Provision SP01040 imposes the following time restrictions:
  • No work during weekday peak hours (6 - 10 AM and 4 - 8 PM)
  • No work on Tuesdays and Wednesdays overnight, for track maintenance
  • Only one track available mid-day, evenings and weekends
  • Two tracks will only be available in the early morning hours Friday - Tuesday.
The limits defined in SP01040 do not include time for sending crews and equipment to or from the work site, known in construction jargon as "mobilization" and "demobilization".  An hour is eaten away from the beginning and end of each work window for this purpose.

If you want to analyze a typical work week on an hour-by-hour basis, you can define six different track availability states.  Each state has associated to it an availability factor, which you can think of as how many tracks are available to perform productive work (i.e. re-signaling or constructing the overhead contact system).

Availability StateAvailability Factor
No access0
Mob/Demob for 1 track0
Mob/Demob for 2 tracks0
Single track available for work0.75
Mob/Demob for 2 tracks with 1 track already available1
Both tracks available for work2

During periods of mobilization or demobilization, the work window is technically open to the contractor, but no useful work can occur since crews are busy moving equipment and materials to/from the work site.  When a single track is available for work, trains passing on the other track will occasionally interrupt the work, which is why the availability factor is 0.75 rather than 1.  This typically accounts for 2 trains passing the work site every hour, causing work to cease for 15 minutes due to worker safety protocols.  When mobilizing both tracks for the contractor, these passing trains cease and the availability factor increases to 1.  The ideal situation is when both tracks are shut down and the contractor has full control of the work site.

Geographical Windows

The corridor has been divided into geographical segments, at least some of which must remain open at all times to allow northbound and southbound trains to meet and run past each other.  Each segment has a certain length (measured in route-miles).

SegmentLength (miles)
Segment #1, MP 0.3 - 8.0 (CP 4th to CP Sierra)7.7
Segment #2, MP 8.0 - 29.1 (CP Sierra to CP Alma)21.1
Segment #3, MP 29.1 - 44.5 (CP Alma to CP De La Cruz)14.8
Segment #4a, MP 44.5 - 47.5 (CP De La Cruz - CP Alameda)3.0
Segment #4b, MP 47.5 - 51.1 (CP Alameda - Tamien)3.6
Yard Facilities (4th & King, CEMOF, San Jose)3.0

Note that various yard facilities are assigned 3 route miles (6 track miles).

During the first phase of electrification, work may only occur in segments 2 and 4, with both tracks open in segments 1 and 3 to allow trains to meet.  Then, following an adjustment to the timetable, the second phase of the work will occur in segments 1 and 3, with both tracks open in segments 2 and 4 to allow trains to meet.  This allows Caltrain to maintain hourly service in both directions during mid-day, evening and weekend periods, single-tracking as needed around electrification work sites.

Labor Costs

Let us loosely define a unit of labor to perform electrification work on one mile of track for one hour (however many people that may actually take).  One labor unit is multiplied by the number of track miles and the number of hours to calculate a burn rate, or how much the labor will cost during any given period of time, assuming the contractor makes full use of the work windows.

We will assume that when both tracks are open, efficiencies can be realized so that only 1.5 labor units (rather than 2) are required to work on 1 route-mile (2 track-miles).  We can then assign a labor cost for each track availability state defined above:

Availability StateHourly Labor Rate
(per route mile)
No access0
Mob/Demob for 1 track1
Mob/Demob for 2 tracks1.5
Single track available for work1
Mob/Demob for 2 tracks with 1 track already available1.5
Both tracks available for work1.5

The work is performed by skilled union workers, whose hourly cost is not always the same.  While weekday work can be performed in shifts at no additional hourly expense, weekend work is another matter.  Depending on the union and the trade (the RFP contains hundreds of pages of union wage rate tables), weekend work can cost up to twice the rate of weekday work.  Let us assume overtime cost factors in as follows:

Day of WeekOvertime Factor
Monday - Friday1
Efficiency Metrics

Now let's pull all these assumptions together and come up with three metrics.
  1. The first metric is average track avaibility, measured in track-miles.  It measures how much of the railroad is available for actual productive electrification work, as opposed to shuffling workers and equipment or dodging out of the way of trains.  Average track availability is inversely proportional to how long it will take to complete the work.  If you double the amount of available track, the job can be done in half the number of weeks.  There are limits to this assumption, of course, but for sequential tasks requiring direct access to track, such as re-signaling and constructing the overhead contact system, this inverse relationship is quite reasonable.

    The way to compute average track availability is to assign each hour of the week a track availability state, based on the rules set out in SP01040.  Then, we multiply the availability factor (associated to that state) by the number of route-miles in that segment to calculate how many track-miles are available for work in that particular hour in that particular segment.  We can repeat this calculation for every hour of the week (24 x 7 = 168 hours) and for every segment.  Finally, we can add it all up and divide by the total number of hours in a week to figure how many miles of track are available on average.

    But it's not quite that simple.  Since the work is divided into two geographical phases, we must first add up the availability for segments 2 and 4 (Phase 1) and then separately add up the availability for segments 1 and 3 and the yards (Phase 2).  The average track availability for Phase 1 and Phase 2 is then averaged; this average is weighted by segment lengths to serve as a proxy for duration of each phase.
  2. The second metric is burn rate, measured in labor units per week.  It measures the rate at which money is spent on all the work, including not just actual productive electrification work but also the shuffling of workers and equipment and the dodging out of the way of trains.  This metric assumes that the contractor makes full use of the available windows, and that no additional hourly expenses are incurred outside of the work windows (e.g. due to the work not filling a full 8-hour union shift).

    The way to compute burn rate is to multiply the hourly labor rate (associated to each hour's track availability state) by the number of route-miles in that segment and the overtime factor for that particular day of the week, to calculate how many labor units are expended in that particular hour in that particular segment.  Once again, we need to be careful how we add up the labor for Phases 1 and 2, using the same partial sums and weighted averages as for track availability.
  3. The third metric is installation efficiency, measured in labor units per week per available track mile.  It measures how much of the labor is expended on actual productive electrification work, as opposed to unproductive tasks such as the shuffling of workers and equipment and the dodging out of the way of trains.  It serves a rough measure of the overall cost of tasks requiring access to the track, such as building the overhead contact system and re-signaling.  It is defined simply as burn rate divided by average track availability.  A lower number is better, indicating that a given length of track can be completed using less labor.
Four Scenarios

Armed with these metrics, we can analyze and compare a variety of electrification scenarios, including the baseline scenario specified in the RFP per Special Provision SP01040, and other scenarios of our choosing.

For the detailed calculations that support each scenario, or to explore your own scenarios and change any of the assumptions, you can download this Excel spreadsheet.
  1. Baseline Scenario: Let us scrupulously apply the work window restrictions from Caltrain's RFP, per SP01040.  Phase 1 has an average track availability of 13.3 track miles, while Phase 2 comes out to 12.1 track miles.  The weighted average of the two phases yields an average track availability of 12.7 track miles.  Bearing in mind that Caltrain has over 100 track miles to be electrified, this works out to a paltry ~12% of the railroad being available, a reflection of the extremely restrictive work windows.  This does not bode well for the program schedule, since having so little of the railroad available to the contractor will draw out the duration of all activities requiring access to the tracks.

    The burn rate works out to 3934 labor units per week, much of which is spent on mobilization and demobilization, as well as on weekend overtime work.

    The installation efficiency is 309 labor units per week per track mile.  When you consider that there are only 168 hours in a week, that is a terrible score indeed.
  2. Weekend Shutdown Scenario: One way to improve the average track availability is to completely shut down the railroad on weekends.  While this concentrates the majority of labor onto weekends when overtime rates are high, it opens up a 54-hour long period of uninterrupted access to segments 1 through 4a, while segment 4b and the yards remain partially open (to support tenant railroads and Caltrain maintenance activities).  This allows weekend work to be performed simultaneously in all segments, during both Phase 1 and Phase 2.

    Not surprisingly, average track availability improves considerably, with 35.3 track miles for Phase 1, 35.6 track miles for Phase 2, and a weighted average of 35.4 track miles.  By shutting down the railroad on weekends, we effectively tripled the amount of track access afforded to the contractor.

    The burn rate goes up quite a bit, because the entire railroad is being worked on every weekend.  The total works out to 8044 labor units per week.

    The installation efficiency is 227 labor units per week per track mile, a savings of 27%.
  3. Friday + Weekend Shutdown Scenario: The next possible step is to shut down the railroad on Fridays to extend the weekend work window to three days.  This has the advantage of increasing availability during a non-overtime weekday, but it is disruptive to riders who need to commute five days a week.  Weekend access increases from 54 hours to 78 hours, again with all four segments being worked simultaneously.

    Average track availability increases to 45.4 track miles.  Burn rate increases to 9144 labor units per week.  Installation efficiency improves to 201 labor units per week per track mile, a savings of 35%.
  4. Total Shutdown Scenario: The most draconian possibility is to shut down the railroad entirely.  It would be extremely disruptive for riders.  It could very well gridlock the highway 101 corridor, and in so doing, drive home the value of Caltrain for hundreds of thousands of commuters who never use Caltrain.  It would leave freight customers high and dry.  On the plus side, it would enable a coordinated construction "blitz" to complete the work at lower cost and far faster.  Electrification could even be combined with other projects such as grade separations.  Segment 4b and the yards would remain partially open (single-tracked) for the tenant railroads that use the southern end of the corridor.

    Average track availability would shoot up to 98.2 track miles.  Burn rate increases to 15600 labor units per week.  Installation efficiency improves to just 159 labor units per week per track mile, a savings of 49% (half off!)
Here are some graphs to summarize the results of this analysis.

You might wonder about the point of this exercise.  The RFP is closed and all the bids are in, so isn't all this overcome by events?

Word has it that the bids came in much higher than Caltrain expected, with contractors blaming the restrictive work windows for the higher cost.  Caltrain is now scrambling to scrape together even more funding than the $958M they thought electrification would cost (not including new vehicles).  Recall about half of that sum was estimated for re-signaling and building the overhead contact system, tasks where cost and schedule are strongly driven by work windows.

Shut Down This Railroad!

The right answer isn't to go digging between couch cushions for another several hundred million dollars.  The right answer is to shut down this railroad, because trying to electrify without shutting it down is like trying to change a flat tire without stopping your car.  A weekend shutdown would speed the work by a factor of nearly three, and reduce cost by about $150 million.  Shut down three days, save $200 million.  Shut everything down, save nearly $300 million.  Okay, maybe don't shut everything down, but at the very least, the weekends must go.