Whistle Stop Trail Bridge

The Whistle Stop Bridge, currently under construction, is a cooperative venture between the US Forest Service and the Alaska Railroad to make the Alaskan backcountry more accessible. This bridge is located along the Alaska railroad between Portage and Moose Pass, Alaska. The area is accessible to recreationists by a self-propelled rail car. The Glulam Bridge will span 282’ and cross the Placer River and when complete will be the longest clear-span timber bridge in North America.

The USFS solicited proposals and considered several design-build options but settled on a design submitted by Western Wood Structures through Patrick Engineering, a General Contractor from Denver, Colorado. To meet the Forest Service’s preference, the bridge design is a Camelback Truss style which is typical of many bridges built in the early 1900’s.

The bridge was pre-fabricated and trial assembled at our facility prior to pressure treatment. Due to its length, we could only pre-assemble three of the five 56’ sections at a time.




The bridge components were shipped to Anchorage by barge and railed to the site for final assembly. The installation scheme called for assembly to take place on either side of the river. Pinned connections were used in the bottom chord splices to facilitate assembly and erection.




Western Wood Structures furnished a superintendent to assist the Contractor in the truss assembly.

Ultimately, hikers will be able to safely cross the Placer River to access the spectacular Spencer Glacier and not be tempted to use the existing railroad trestle.

Dana Hall Repairs

Dana Hall, on the campus of SUNY College of Technology in Canton, New York, was constructed in 1969. It was built to accommodate the College’s athletic teams and physical education classes. The main framing consisted of Glulam arch frames spaced at 18’ centers spanning 108’-6”.

About two years after the building was opened, cracks were noticed at the moment splice locations which concerned the owners enough to call for a series of inspections. It was determined that the cracks were not structurally significant as long as they did not propagate but since the cracks were evident in the same location in each of the Glulam frames, this confirmed that an inherent issue existed with the design. It was decided that the splits would be “monitored” to make sure they didn’t progress further.

In 1998 Canton experienced a heavy snow storm. In 2006, maintenance personnel noticed that the cracks had propagated and opened further. Following another inspection, an attempt was made to repair the most heavily split arch frame using lag screws inserted from the bottom of the arch. But new splits occurred after the lag screws were installed near the tops of the new lags so a second attempt was made to close the splits using steel angles and an HSS section to clamp the arches.

These attempts proved unsuccessful so the College began exploring the cost to demolish the building. Initial demolition estimates were in the vicinity of $2.3 million. But before the final decision was made to demolish the building, the College decided to make one final attempt to repair the Glulam frames. An internet search led them to Western Wood Structures who was hired to perform an inspection, complete a structural analysis, and make recommendations for a permanent solution.

The College decided to accept Western Wood’s opinion that the frames could be repaired as well as brought to current code and the decision was then made to advertise the job to the general public on a design-build basis. Western Wood turned in a bid and was eventually awarded the contract for just over $1.1 million.

There were four repair and code upgrade methods used by Western Wood Structures to complete the necessary repairs:

1. The frames were post-tensioned due to being over stressed in bending;

2. Additional laminations were added due to being over stressed in bending;

3. Shear dowels were installed to restore the shear capacity of the members. Some of the holes drilled into the arch frames were 54" deep;

4. Side plates were installed at the moment splice locations to transfer the reaction of the beam to the arch section.

Dana Hall has been saved from the wrecking ball and today, SUNY College of Technology has a multi-use building that will safely serve their needs for many years to come.

Dana Hall Repair White Paper

The Angus Bowmer Theater

On June 16th of this year, a loud “cracking” sound was heard by crew members rehearsing Shakespeare’s “Measure for Measure” so owners of the 600-seat Angus Bowmer Theater in Ashland, Oregon decided to have the sound checked out. Using a catwalk for access, a crew member discovered a large crack in the main Glulam carrying beam above the stage so the decision was made to evacuate the building. The following day, an Ashland City engineer examined the beam and declared the building unsafe for public usage. Alternate plans were then adopted by the Oregon Shakespeare Festival (OSF) so the show could go on.

Adroit Construction of Ashland was hired to shore the massive 14.5” x 78” x 70’ Glulam. Once the shoring was in place, the roof was secure. OSF then hired two engineering firms, Marquess & Associates of Medford and KPFF of Portland, to study the problem and three emergency repair options were considered. In the end, a proposal from Western Wood Structures to design and implement a repair scheme was accepted. Our design was preferred because it did not add a significant amount of weight to the existing roof structure and because the work could be completed in a timely manner.

The Glulam had been split so badly that it was functioning as two small beams rather than one large one. With shoring towers in place, Adroit Construction successfully jacked the beam back to its original position and closed the crack. Western Wood Structures arrived on site July 5th to begin the repairs.

Our first task was to seal the outer surfaces of the beam with an epoxy paste to prevent epoxy leaking. After roofing was removed to allow access to the top of the beam, we then drilled 180 holes into the beam which measured 1-3/8” in diameter and approximately 66” in depth. One inch diameter rebars were placed in the holes and then filled with epoxy, 105 gallons total. Once the epoxy cured, the “shear dowels” had essentially “stitched” the beam back together.

Finally, the beam was post tensioned using steel cable anchors, a steel cable guide, and 15 high strength cables in order to increase its carrying capacity and to meet current code requirements. The cable anchors were installed to the soffit of the beam also using rebars set in epoxy-filled holes.

In our review, we determined that the cause of the failure was attributed to a connection detail on the original drawings. 9” x 32.5” Glulam purlins that measure framing in to one side of the failed beam were attached in hangers near the bottom of the main beam and below its neutral axis which can cause excessive tension perpendicular to grain stresses in the member. Current timber construction standards identify this as a connection detail to avoid.

Our work was completed on July 17th several days ahead of schedule. OSF has announced that the Bowmer will re-open on August 2nd. The owners and Shakespeare fans can rest assured knowing the next play will be performed beneath a main carrying beam that is stronger today than it was when originally manufactured in 1969.

America's Car Museum

This beautiful timber building, designed to meet the requirements of Heavy Timber Construction, is currently being built in Tacoma, WA. and is scheduled for opening in May 2012. The 165,000 sq. ft. four-story museum will house vintage cars, many of which were collected and owned by Harold LeMay, who owned a succesful refuse company in Tacoma. Mr. LeMay amassed the world’s largest private collection of cars.

Western Wood Structures supplied and installed this unique Glulam roof system and also has design responsibilities for the roof structure. The timber roof framing took about 3 months to install. The museum is being built on land donated by the city of Tacoma adjacent to the Tacoma Dome, another Western Wood Structures project.

The museum is dedicated to the preservation of automotive history and will be utilized for special events such as weddings and corporate meetings and conferences. It will also feature the availability of banquet facilities as well as an outdoor field for festivals and concerts.

Central Lutheran Church Steeple

Upon completion of renovations to their church in 2005, members of the Central Lutheran Church in Northeast Portland discovered that their Glulam steeple and cross had rotted. A decision was made to tear the structure down due to a lack of funds and liability concerns should the structure collapse.

But the city of Portland had named the Pietro Belluschi designed building a historic landmark in 1970 and city officials informed the congregation that they would have to replace the landmark steeple or face heavy fines. Furthermore, the tower and cross had to look exactly like the original one.

The tower was fabricated, stained, and pre-assembled in four large sections at the Western Wood Structures facility in Tualatin and trucked to the site for final assembly. The City allowed a few allowances because of current building codes but the cross and steeple are very close in appearance to the original.

Three years after the original steeple had been taken down, the new one was lifted into place with two cranes and can be spotted looming 100 feet above the sidewalk in its original position.

Gallatin Field Terminal Expansion

Construction of the new terminal at Bozeman Gallatin Field is well under way and is on schedule for completion this summer. This expansion will double the passenger capacity of the airport and is needed to meet the demands of business travelers and visitors in and out of southwest Montana. The three story terminal building features exposed Glulam construction and serves as the lodge-themed center piece for the airport.

Western Wood Structures supplied the Glued Laminated members and Simpson hangers to the General Contractor, Martel Construction of Bozeman. The job required 18 pages of shop drawings to detail and schedule the nearly 2,000 individual laminated beams, purlins, columns, and trim pieces. The Glulams were manufactured by QB Corp. of Salmon, Idaho and the difficult fabrication was performed in the plant.

Educational Seminars

Western Wood Structures is presenting two educational seminars next week to structural engineering groups.

The first seminar will be presented to the Structural Engineers Association of Maine on Monday February 28th starting at 5 pm. It will be held in the conference center of the Holiday Inn on Riverside Street in Portland, Maine.

The second seminar will be presented the following night to the Structural Engineers Association of Rhode Island. It will be held at the offices of Odeh Engineers, Inc. in North Providence, R.I. starting at 4:45 in the afternoon.

Paul Gilham, Chief Engineer for WWS, will be the speaker. The seminars will focus on the Rehabilitation and will highlight common problems that existing timber beams and trusses can have as well as what solutions are available to building owners for any required repairs and code upgrades. Case study examples will be used to illustrate the processes used by WWS for analyzing older structures as well as for the implementing of repairs.