Tag Archives: bridge

Building a Bridge One Bit at a Time

One of our work projects includes the construction of a long span bridge for the light rail line to run over.  I have been down on many occasions since the construction started on this section but much of the early work was the preparation of the ground and the creation of the foundations for the final bridge.  We now have the piers in place and the construction of the bridge itself is underway.

This type of construction involves casting the bridge in sections in place rather than offsite and then bringing them in.  Steel supporters called travelers, hold the formwork in place as each section is cast.  When it is cured, the traveler moves out onto the new section and the process is repeated.  This happens symmetrically about the pier, so the bridge grows out in both directions at once keeping everything balanced.

The process moves quite quickly so, each time I go down, the bridge has got noticeably larger.  There are actually to sections happening at once to make the two halves of the bridge.  They grow towards each other, and the final casting will connect the two cantilevered spans to complete the bridge.  That will happen later in 2024.  The section of the bridge is hollow so it will be possible to access the insides of it in the future.  If I get a chance to go inside at some point, expect more images here.

Rails on the End of the Bridge

The railway that runs from Seattle up to Everett and either on to Vancouver or east across the Cascades crosses a bridge that is just outside the locks at Ballard.  The bridge is a bascule bridge and, since there is quite regular boat traffic including sailing boats with high masts, it is frequently opened.  The low winter light does a nice job of illuminating the underside of the deck of the bridge when it is open.  I was more interested in the shapes at the end of the bridge where the rails end.  They are clearly shaped to interlock with the opposite rails on the bridge approach and also to have a shape which allows the wheels to smoothly pass over without some sudden impact forces.  As they stand up in the air, they strike me as rather fascinating.

Another of Brunel’s Creations

As we walked back towards the docks in Bristol after going up to see the Clifton Suspension bridge, we crossed over to the other side of the locks that are at the end of the harbor.  There we came across another artifact of the industrial history of the city which I knew nothing of previously.  Since it is Bristol, no great shock that it was something that Brunel created.

This was an old swing bridge that would span the locks.  Apparently, it was in use for many years before being withdrawn when a modern bridge was built to supersede it in 1968.  It was close to being scrapped at that point but thankfully wasn’t.  Now it is sitting on the side of the lock while waiting to undergo restoration.    It certainly needs some work at this point, and it is strange to think that it was the main route across the locks for decades.

Preparing for a Major Bridge Structure

One of the projects I am involved with includes some significant civil engineering and construction work.  Part of this is to build a long span bridge across a dip alongside an interstate.  The work is progressing quickly so things are changing fast.  By the time this post goes live, there will be a lot more to see on the site.  However, when I took these shots, they were preparing to pour to concrete shafts that will support the bridge piers.  The amount of work in preparing the area to stabilize the ground, drill the shafts, have access to the site and have the abutments at each end is huge.  Here are some shots of the work underway at that point.

Cross Kirkland Connector’s New Bridge

The disused railway lines along the eastern side of Lake Washington are progressively becoming trails for the local community.  One section of track that runs through the middle of Kirkland is know as the Cross Kirkland Connector.  This will run up towards Woodinville in due course.  The northern end of the trail for a long time was Totem Lake when the trail came to 124th St.  This is a busy road and crossing it was not a simple process.  As part of the development of the trails, a bridge has been under construction for a while now and it recently was opened to the public.

This bridge is a short distance from my office, and it would provide a useful potential connection if I was to start cycling to work again.  I walked down to the bridge one lunchtime to see how it looked.  The styling of the structure over the road is quite flowing and I had driven underneath at various times in construction, so I was familiar with the general shape.  To get down to the street level, a circular ramp is on the north side, and this loops around near the lake and marshlands.

There are some overlook areas built out from the ramp to encourage people to linger a little.  A few bikes and pedestrians passed over in the short time I was there so I hope there will be a good amount of traffic to justify the investment.  When all of the trails are complete, it will be possible to ride from Renton to the Skagit County line without needing to use the road.

View From The Bridge

Arriving back in Seattle from our UK vacation, we got to use the new international arrivals facility.  This includes the bridge from the South Satellite.  This crosses the taxiway between the two terminal buildings.  It’s not like you have the time to hang around in the area and I imagine they might discourage you from doing so.  However, you can grab a few shots of the aircraft beneath you while crossing.  The reflections were a bit of a problem but I am not going to be there very often so make the most of it!

SR99 Bridge Over SR509

WSDOT is in the process of building a new part of SR509 that will connect I-5 to the rest of SR509 on the west side of the airport.  The alignment that the new road is taking cross SR99 at the same place that we are currently building the light rail extension.  To avoid making life too complex, WSDOT funded Sound Transit to build the bridge for SR99 that is needs as part of the light rail construction program.  The contractor diverted SR99 around the work site and then excavated the area where SR509 will go.  A new bridge was built over this and then it was all filled in underneath.  The road then was laid on top of the new bridge.

Since these pictures were taken, the road has been re-opened.  However, at this tie, they were finishing the pours of concrete for the new bridge and too tie it in to the existing roadway.  This view is now gone so it was a narrow window to see the bridge.  I was lucky to see it at various stages of its construction.  In due course, WSDOT’s contractor will come in and remove the earth under the bridge and build the SR509 roadway.  That will happen pretty soon.

Tokul Trestle Bridge

The thing that attracted me to a stroll along the Snoqualmie Valley Trail was the presence of an old railway trestle bridge.  Known as the Tokul Trestle, it seemed to be on a curve over a deep valley based on what I could see on Google Maps.  What I didn’t know was how much you could see of it from either side.  Only one way to find out I guess.

It wasn’t a terribly long walk from where I had parked the car to get to the trestle.  When you don’t know a route, it always feels a bit longer but walking back seems a far shorter journey.  Since the trestle was on a curve and the route was very tree lined, it was pretty much out of sight until I was nearly upon it.  The majority of the trestle seems pretty old but there is a center section that seems to be more modern.  Of course, that could have been there for ages and the whole bridge was maybe restored when the trail was being created.  If I had done some research, I might have been able to tell you!

The curve of the bridge is quite gradual and, as I had wondered, the approaches are tree lined which makes getting too much of an angle on the bridge tricky.  A drone would be a very handy thing for getting a broader view of the bridge or being down on the river bed below.  Not sure who owns that but there is a firing range down there somewhere which I could hear along part of the walk.  You can get down on the sides of the bridge at each end to get a bit more of a view of the structure and I did check that out.  Since I was alone in an area without much cellphone reception, though, I didn’t get too adventurous.

There is something about trestle bridges that really fascinates me.  They seem quintessentially American to me.  In the UK, rail bridges of old are either iron or brick.  They look impressive too and make for great photo subjects.  However, the trestle is something that evokes images of old steam locos crossing the country with wide flared smokestacks.  The idea that they are still around and in good working order continues to surprise me.

Old Trestle at Whatcom Falls

A railroad used to run through what is now Whatcom Falls Park.  While the tracks have now gone, a trestle bridge across the water still remains.  I may have lived in the US a long time now, the presence of trestle bridges still fascinates me.  They have a look of Victorian railroads about them but many have survived.  In the UK, old bridges are either iron or brick with multiple arches.  The trestles have a distinctly American feel to them.

There were some barriers around the end of the bridge while we were there.  Checking out some photos online, it looks like the rails used to be suspended across some of the space.  Maybe these have been removed to stop people getting up there.  Fortunately, the majority of the bridge is still intact.  I wonder what happened to the track bed.  The rails are visible up on the top with ties (sleepers) between them but no support which suggests. Train would have had a rough ride.  There must have been more there at some point.

Deception Pass Bridge Maintenance

While on our trip to Whidbey, we made a short stop at the North beach in Deception Pass State Park.  This is the beach that is closest to the bridge across the pass.  I was hoping it might be possible to get a nice shot of the bridge but I was disappointed to realize that the maintenance work underway on the bridge has resulted in the structure being covered in a ton of material.  No chance to get anything exciting from that.  If you looked closely, you could make out some of the maintenance team up on the bridge in their hi-viz clothing.  That is not a job for which I would be well suited.