Cajon Pass: From double to triple-track
A massive capacity expansion project on BNSF’s busy Cajon Pass line is due to be completed by the end of this year. David Lustig reports from California
TO ACCOMMODATE the ever-increasing flow of goods between Pacific Rim countries and the USA, BNSF Railway is investing steadily to expand the capacity of its busy main line through the San Bernardino Mountains that separate the ports of southern California from the rest of the nation.
In mid-2007, the company began triple-tracking a 25 km section of its Cajon Subdivision, between Keenbrook and Summit, atop Cajon Pass. This is a key part of the Los Angeles - Chicago 'Transcon' corridor.
Over the past decade, BNSF has been working steadily to eliminate the remaining single track sections along the Transcon and add additional main tracks on key sections. Several of these investment projects have faced demanding topography, notably at Abo Canyon in New Mexico, but Cajon Pass has proved particularly challenging.
The line climbs out of the Los Angeles basin on gradients ranging from 2·2% to more than 3%, requiring strict speed restrictions for safe operation both up and down the hill. This reduces line capacity, requiring the addition of a third track to maintain fluid operations as traffic volumes increase.
BNSF is pouring more than $90m into the upgrade, which is due to be completed by the end of this year. More than 200 BNSF staff and contractors are at work on the project, some bringing specialist skills from other industries or previous investment schemes.
Construction of the additional track and its connecting crossovers must be done while the trains keep rolling - anywhere from 80 to more than 100 trains a day use the line, including Union Pacific movements via trackage rights and Amtrak's Chicago - Los Angeles Southwest Chief.
According to Bob Brendza, BNSF's Director of Facility Development, the Keenbrook - Summit upgrading is the third of three consecutive expansion projects. The first covered the 8 km segment from Baseline, just outside San Bernardino, to Verdemont, and was completed in August 2004. The next 9·6 km from Verdemont to Keenbrook was finished in January 2006.
The two existing tracks between Keenbrook and Summit were laid at different times, and follow separate alignments in places. Between Cajon and Summit the third track will parallel the less steeply graded No 1 track. From Summit, the extra track connects into an existing loop line continuing east for a further 4 km. From that point, the route will remain double-track to the important junction at Barstow.
Brendza does not expect this to cause any adverse effect on trains waiting to head east. Because freight trains run at higher speeds on the sections either side of the pass, there is sufficient capacity on the existing two tracks. It is only the slower train speeds up and down the pass itself, along with the inherent challenges of mountain grade operations, which create the bottleneck.
According to BNSF, completion of the triple-tracking will expand capacity on this segment of the Transcon from 100 to more than 150 trains per day. Average train velocity will be improved, offering efficiencies for both transport and maintenance activities.
'We've had days where well over 100 trains have been operated over the mountain', says Brendza. 'Such sustained volumes don't provide an adequate cushion to allow recovery from unanticipated events, and place strain on maintenance resources attempting to get time to work on the track, sometimes resulting in trains having to stop. When this project is complete we will have increased the sustainable capacity of the line to 150 trains per day, which will ease the flow over Cajon Pass.'
Forward planning pays off
One of the reasons Brendza and his Engineering Manager David Miller feel the upgrading has gone so smoothly is the tremendous amount of planning undertaken before physical construction began. Planning for the project began as far back as 2003. Throughout the process, company officials are working closely with local, state and federal government agencies.
At the outset, civil engineers and environmental consultants were brought in to determine what needed to be done, not only to build the extra track, but also to protect the environment - at this point the line runs through the San Bernadino National Forest. BNSF worked closely with various government and regulatory agencies to ensure a balanced approach to development, as well as allowing for early input and establishing support from external stakeholders.
'The previous independent triple track projects were easier', admits Brendza. 'It was the third segment - the one we're working on now - that has taken more than two years of preparation to get all the permits in place.
'On a project of this magnitude, success comes from a combined developmental approach which balances engineering design with environmental sensitivity in an effort to optimise the ultimate project cost and delivery timeline', he explains.
'If we can avoid potential environmental impacts by designing around them, we want to ensure we've fully analysed the alternatives. For example, instead of cutting back a slope that contains a protected species or habitat, or placing fill in a river, we evaluate the potential to avoid impacts through the construction of retaining walls. Our first preference is to avoid. If we can't avoid, we attempt to reduce impacts; and, if we can do neither, we look at how the impacts can be mitigated.'
Brendza says BNSF makes it a priority to work closely with the US Army Corps of Engineers, and other regulatory agencies including the Forest Service, the Fish & Wildlife Service, the Environmental Protection Agency, the California Department of Fish & Game, the Regional Water Quality Control Board, and the State Historic Preservation Office. Involving the agencies early in the process shaved years off the project development process, he estimates.
As an example, the Army Corps of Engineers indicated that the typical timeframe for getting permission for a linear transport project of this sort would be 6·4 years, but the permit for the Cajon project was obtained in 14 months. 'Meetings were carefully designed to obtain buy-in, set achievable expectations and address problems when they were still small', explains Brendza.
Nevertheless, not all contingencies could be avoided. In October, massive wild fires swept across southern California, and some came dangerously close to the BNSF's right-of-way in the Cajon Pass area. This caused the line to be shut down temporarily, not only for trains, but for construction work as well.
Before and after
As part of the triple-tracking project, the route's two existing tunnels, of 122 m and 165 m in length, are due to be removed this month. A temporary diversion track is being laid so as not to impede daily train operations. The earth covering over the tunnels will then be removed and the concrete linings broken up and hauled away. A second track will then be constructed parallel with the original through a large cutting where the tunnels have stood since 1913. Removal of the tunnels will allow more efficient track maintenance, as well as providing improved access during operation.
In total, 18 high speed turnouts are being installed or repositioned, at Summit, Silverwood, Alray, Cajon, and Keenbrook so that trains can be switched from one track to another without slowing down. Miller says every control point is being rebuilt. 'Every signal a train goes by will be new', he emphasises. Some bridges will be new, and others will be modified to take increased loads and stresses. Wherever possible, the existing infrastructure is being upgraded at the same time. For example, concrete sleepers are being installed throughout, except on bridges and through turnouts, and all three tracks are being relaid with 70 kg/m rail.
More than 700 000 m³ of material must be moved, according to Miller. 'We'll have a lot of excess dirt on our hands', he notes, 'but we've found a home for all of it. And, more importantly, we have completed the first six months of this huge project safely and with minimal delay to the trains.'
Brendza says 'Cajon is one of the most critically important and professionally-fulfilling projects of my career', given the technical challenges, the number of public agencies involved, the level of internal and external teamwork and the high level of co-operation required. But it is all worthwhile, he continues, because 'it will eliminate one of the biggest capacity constraints on the southern transcontinental railroad'.
- CAPTION: Three front-end loaders are used to push a new universal crossover into place just west of Alray. As soon as it is in place, engineers will bolt in the pre-fabricated trackwork
- CAPTION: BNSF's Director of Facility Development Bob Brendza (left) and Engineering Manager David Miller undertake a ‘roll by’ inspection on a westbound train just east of Blue Cut, 25 km north of San Bernardino
- CAPTION: An eastbound train approaches Summit, one location where the third track will be laid close to the existing alignment just to the right of the train
- CAPTION: An eastbound double-stack container train nears Eastwood, about 1?6 km from the summit
- CAPTION: A westbound BNSF train approaches the 165 m Tunnel 2 on one of the main running lines. There are two tunnels on the exiting line, and both will be demolished as part of the upgrade project