The 8th Wonder (Once)

A post earlier this week related our recent meet-up with blogger friends in PA. Linda and Bob were wonderful and very informative tour guides who introduced us to an amazing PA sight at Kinzua Bridge State Park. Spoiler Alert: This is a long post.

Admittedly, we are always interested in sites new-to-us and especially ones with a historical background. What we saw at this 339-acre Pennsylvania state park near Mt Jewett was amazing. We can understand why it was selected by the Pennsylvania Department of Conservation and Natural Resources (DCNR) and Bureau of Parks as one of 25 Must-See Pennsylvania State Parks. 

The park's highlight is the Kinzua Sky Walk extending 624 feet into the Kinzua Gorge featuring panoramic views. Once known as the Kinzua Viaduct, this engineering marvel was once the highest railway bridge in the world. Six of the bridge's 20 towers were taller than the Brooklyn Bridge. In 1977, it was listed as a Historic Civil Engineering Landmark. 

Although the state park name uses Kinzua Bridge, the original and correct name is Kinzua Viaduct, both terms are used interchangeably today. Kinzua Bridge became a common, widely accepted name among the general public rather than viaduct.. 

A major difference between the terms is purpose. While a bridge usually spans a single gap, like a river or roadway, a viaduct is a type of bridge comprised of various spans over uneven terrain with multiple supports to maintain a consistent, level grade. Since this structure included a railway across the Kinzua Creek Valley, Kinzua Viaduct is the more accurate and historical term that will be used herein. 

The Kinzua Sky Walk is the feature in Kinzua Bridge State Park

As for this post title, there's no actual Eighth wonder of the world; however, this designation was unofficially applied to the 1882 wrought iron Kinzua Viaduct which for 2 years held the record as the tallest railroad bridge in the world. Eight years later (1890), the bridge was dismantled and rebuilt with steel. It survived for over a century until the structure met the force of Mother Nature (details to follow).

The Back Story — construction, rebuilding, disaster, rebirth

Thomas Kane

In the 1880s, the half-mile wide and 300 feet deep, Kinzua Creek Valley stood in theway of commerce since the New York, Lake Erie and Western Coal Railway (NYLEW) needed to transport coal, lumber, oil and other resources to Buffalo's markets faster. The fastest way would be to build a bridge across the valley compared to putting down eight miles of track over rough terrain to carry trains loaded with the materials. Railroad president Thomas Kane urged investors to open their wallets to fund the construction of a bridge to transverse the gorge. Kane, who wheezed from a chronic lung condition and also had been injured in the Civil War, lived long enough to see his dream become reality.

1882 construction of the wrought iron Kinzua Viaduct and some of the workmen

Construction of the iron viaduct began in May 1881, staring with the placement of stone piers. It took 6 to 10 months to do the pier work with some months off for winter. Erection of the tubular iron began nearly a year later in May 1882. Amazingly, it was in completed in only 94 days. A work force of approximately 100 to 150 men placed 110 piers with over 1,552 tons of wrought iron at an estimated cost between $167,000 and $275,000 (back then). The viaduct was designed by Octave Chanute, a prominent civil engineer who advised early aviators including the Wright brothers.

Visitor center display of viaduct engineer Bonzano (L) and designer Chanute (R)

The bridge's 110 sandstone masonry piers were quarried from the hillside used for the foundation of the bridge. The original viaduct was 301 feet high, 2,053 feet long and weighed over 3,100,000 pounds. 

Phoenix column construction used for Kinzua Viaduct

Visitors' center exhibit explaining how viaduct was built

Engineer Adolphus Bonzano used a patented design called Phoenix Columns, lighter in weight with greater strength than cast iron columns of similar design. Because of the design of these columns, it was believed mistakenly that the bridge had been built with wooden poles. 

Erecting the original 1882 Kinzua Viaduct with a traveling crane

Bonzano determined that trains could safely cross the viaduct at 5 mph sending vibrations down the iron structure like a tuning fork. By 1893, the NYLE&W went bankrupt and merged with the Erie Railroad, the new owner of the viaduct. Less than 10 years later at the start of the 20th century, locomotives were 85 percent heavier and the iron bridge couldn't carry them safely. The decision was made to rebuild the entire structure with steel for both heavier locomotives and longer trains. 

Steel reconstruction of the Kinzua Viaduct in 1890 and some of the workmen

Rebuilt process from wrought iron to steel

In 1990, a crew from the Elmira Bridge Company dismantled the iron structure and rebuilt each tower with steel latticework. Working in 10-hour shifts, some 100 to 150 men completed the project in 105 days. The new steel viaduct had the same measurements and weighed nearly double the original at 6,706,000 pounds. Bolts used to hold the towers to the anchor blocks were re-used from the original bridge. This decision would eventually play a major role in the bridge's downfall.

Vintage photo showing train on steel rebuilt viaduct

Yet, despite this reconstruction, the train's speed limit remained 5 mph. As the bridge aged, heavy trains pulled by two steam locomotives had to stop so engines could cross the bridge one at a time. Lighter diesel locomotives didn't have that limit. 

Vintage postcard showing a train traveling the Kinzua Viaduct

The last steam locomotive in commercial service crossed on October 5, 1950, freight traffic ended in 1959 and the Erie Railroad (owner of the viaduct) sold it to a salvage company in Indiana, PA, for $76,000. When local citizens protested, the salvage company owner, who admired the extraordinary structure, worked with local support groups to save it and offered to sell it to the State of Pennsylvania. In August 1963, then Governor William Scranton signed a bill to purchase the viaduct and adjacent land for $50,000 to create Kinzua Bridge State Park. The viaduct received national recognition and was placed on the National Register of Historic Places in 1977, an honor later rescinded.

A Knox and Kane steam locomotive on the Kinzua Viaduct before 2002

After freight traffic stopped, the Knox and Kane (K&K) Railroad purchased a portion of the Erie Railroad and in 1987 started steam rail trips across the viaduct from Knox to Kane, PA. The trip went through the Allegheny National Park and traveled on the viaduct before returning. 

But in June 2002, the viaduct was closed when an inspection by the Department of Conservation and Natural Resources (DCNR) revealed it needed a full restoration. The fear was that high winds could cause a collapse. Trains again were barred from travel on the viaduct. The K&K railroad lost a major tourism draw so was affected severely. When it suspended operations in 2006, the PA salvage company that had bought the viaduct then resold it to the state, bought the tracks.

Worse news than the end of the excursion train came two months later. In August 2002, the viaduct was closed to all traffic, even pedestrians. In February 2003, an Ohio-based bridge construction and repair company started restoration. 

Aftermath of 2003 tornado shows towers torn from their bases

This was a short lived effort As construction workers were leaving the site in late afternoon July 21, 2003 — disaster hit as an tornado with wind speeds of 73-112 mph struck a side of the viaduct. The F-1 classified storm tore down 11 of 20 towers at the center of the bridge from their concrete bases toppling them to the valley floor. The tornado also snapped and uprooted nearby trees. There were no injuries or deaths reported. (I wondered if this was unusual PA weather. But, an online check showed that while the state averages 16 tornadoes per year mostly in May to July, these can occur year-round.)

Remember those bolts that were not replaced? 

A post-collapse inspection revealed that the 1882 wrought iron bridge had been replaced in 1900 with steel except for the anchor bolts. The anchor bolts holding the bases of the towers were badly rusted. An investigation determined that the viaduct swung back and forth several times before the base bolts failed due to fatigue. The century-old viaduct was destroyed in under a minute. 

Rusted and failed base bolts contributed to the collapse

Towers, which fell intact in sections and sustained impact damage, were left where they fell. The state of PA opted not to rebuild as the cost would have topped $45 million (then). Before the collapse, Kinzua Bridge State Park attracted over 200,000 visitors annually. A decision was made to transform the disaster into a visitor attraction to showcase both the history of the structure and the forces of nature.

Park visitors can hike down to view the collapsed towers left where they fell

As if the situation could not get worse, it did when in July 2004, the viaduct was removed from the National Register of Historic Places after the catastrophic collapse.

Railroad ties twisted after the tornado and currently with all tracks removed

This was because the 2003 disaster changed its physical integrity and it didn't exist as the historic entity for which it had been recognized earlier. The viaduct's removal from the listing wasn't a punitive delisting but caused by its destruction.

But, there was also good news too. In June 2005, the State of Pennsylvania released $700,000 to design repairs on the remaining towers and reinvent the viaduct as the Kinzua Sky Walk. The state's Department of Conservation and Natural Resources (DCNR) put forward another proposal to add an observation deck and visitors' center. 

View below Kinzua Sky Walk

This plan allowed access to a remaining portion of the viaduct with a hiking trail for views of the fallen towers. The Kinzua Sky Walk cost $4.3 million and opened in September 2011. A tourism expert estimated it could bring in over $11 million in annual revenue. The area benefits from visitor spending on food, lodging and other activities. Admission to the visitors' center, sky walk and park are free. 

Lower observation deck of Kinzua Sky Walk

On the Kinzua Sky Walk, visitors walk 600 feet onto the remaining support towers of the former Kinzua Viaduct. The pedestrian walkway is on six restored original towers, yes with new anchor bolts. The 225-foot high observation deck offers a view of Kinzua Creek Valley with 11 twisted and scattered towers at the bottom. The railroad tracks have been removed from the deck. The walkway ends at an overlook with a partial glass floor. Unfortunately, at the time of our visit, a catwalk had been installed for crews to access the underside of the sky walk. The view was obstructed and we couldn't see the ground 225 feet below; maybe another time.

Picture taking platform under the skywalk provides a 3D effect

Highly recommended is the picture taking platform under the sky walk where visitors and photograph themselves and the remaining support towers. The view resembles a 3D effect, similar to the pre-tower collapse.

Front entry of Kinzua Bridge State Park visitors' center

The Visitors Center is accessed at the edge of Kinzua Gorge. Huge steel towers flank the doorway. The building features two exhibit halls with displays showcasing the three E’s – Engineering, Energy and the Environment. 

If you're ever in the vicinity of Mt Jewett, PA, we would highly recommend going out of your way, if necessary, to find and explore this amazing structure. That said, there's limited time to do so in 2025. The Kinzua Sky Walk will close October 31 after its temporary reopening for fall foliage season. The walkway is closed for a multi-year rehabilitation. The next reopening will be fall 2026 if you want to plan ahead..

Even if the viaduct wasn't an actual wonder of the world, the fact that original construction took 3 months, reconstruction took just a half month longer and that it stood for over 121 years since originally built — is amazing. Our thanks to Linda and Bob for introducing us to what we consider a true wonder, even if it's not on the books as such.

View down from the sky walk

On the other hand, if you have a fear of heights, it might be best not to look down over the side, just look straight ahead.

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Aside from photos taken during our visit, all vintage photos used to showcase the Kinzua Viaduct before, during and after restoration were obtained from online sources. These have been used solely for the purpose of documentation. I am grateful for all the sources.