Bridge Doctors

27/02/2023

24/02/2023

24/02/2023

30/01/2022

INTRICATE BRIDGES ... The bridge over the Clarence River at Harwood. The last Waddell type vertical lift bridge built by .

The bridge is made up of a vertical lift span of 37m, six steel Pratt truss spans of 42m and twenty-seven steel girder spans each 21m long. Its got a clearance over the water of over 36m when raised. Just perfection!

Happen to be travelling the Clarence River? You can still book an opening of Harwood Bridge at most times of the year.

For some detailed reading about Harwood Bridge and other lift span bridges have a look at the Moveable Span Bridge Study. It was a study completed by GHD in conjunction with the Environment Branch of TfNSW. ⠀
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TfNSW use these types of studies to help manage their heritage bridges into the future.

You can read the study here https://bit.ly/34nj1XV 😊⠀
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31/10/2021

CATHEDRAL LIKE from below this steel suspension bridge is an incredible beauty.

Designed by engineers David Steinman and Holton Robinson - Steinman was a specialist in the design of suspension bridges. The bridge took the honors of being the longest suspension-type bridge west of the Mississippi River at the time of construction.

Did you know that when the paint colour of the bridge was being chosen, safety advocates wanted the bridge to be painted in stripes of bright yellow and black to warn airplanes.

This bridge is one of the most beautiful bridges in America. What makes it so...

🌉 the distinctive gothic arches in the piers

🌉 The concrete anchorages which contribute to the bridges' strength and stability

🌉 the concrete foundations for the main suspension towers have elaborate architectural detailing

🌉 the colour verde green to blend in with the trees and be part of the landscape

Thanks for these images Kevin Butz and Tyler Collins.

10/10/2021

FACT OR FICTION ... Glebe Bridge at Coraki. Built in 1905 with a long history.

Have you ever heard of the mythical "Brisbane Line"? It was a controversial defence proposal allegedly formulated during World War II. Apparently the northern portion of the Australian continent was to be conceded in the event of an invasion by the Japanese.

The "Line" ran from Brisbane to Adelaide and took advantage of The Great Dividing Range. Of course this strategy was a political hot potato which no party wanted to claim. Even a Royal Commission couldn't locate any documentation regarding the idea.

But hey ... take a look at the holes drilled in the pier column of Glebe Bridge. The story goes that these holes were to take dynamite so the bridge could be blown up , slowing the invasion of the Japanese. Food for thought I reckon.

03/10/2021

DREAMS DO COME TRUE ... Had an amazing opportunity to inspect the balanced cantilever bridge at Bolivia Hill near Tenterfield on the New England Highway.

Any new bridge built has to have a Level 2 inspection prior to Transport for NSW taking responsibility for ongoing maintenance of the bridge.

This allows time for the Principal Contractor to address any defects that may have occurred during construction.

Bridgedoctors personnel got this gig because they have extensive experience in the inspection, construction, design, maintenance and repair of bridges.

Interesting conctruction facts:

🌉 The project cost $134 million

🌉The project involved the construction of 2.1km of new road, a new 320-metre long bridge, wider lanes & road shoulders to improve safety

🌉 The bridge was constructed on an 8.5% longitudinal grade

🌉 Planning for the upgrade began in 2013 - wow over 7 years ago!

🌉 At times this project supported up to 200 jobs including for 50 locals, while 10 local contracting firms helped to deliver the final product

26/09/2021

ORIGINAL MASONRY ABUTMENTS ... The new bridge has been built over original foundations and incorporates the original masonry abutments and a non structural center pier. These items have heritage significance and are still maintained.

This little beauty is just outside the village of Drake in northern NSW. Drake burst onto the gold mining map in 1858 when gold was discovered. Faced with the pressure of thousands of people wanting to travel in search for gold, by 1860 another 1450 kilometers of roads (and bridges) were built.

Bridges constructed in Australia before the 1830s were very simple. It wasn't until the arrival of David Lennox in 1832 that masonry was used in their construction. Who knows ... maybe this was a weekend job for the great engineer David Lennox 🤭

19/09/2021

A MASTERPIECE of Roman engineering - the beautifully preserved Pont du Gard. This bridge was built around the year 50 AD to allow the aqueduct of Nîmes to cross the river Gardon. It peaks at over 48 metres high and crosses the river over a length of 275 metres. ⠀
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Some of the remarkable construction precision of this bridge include:⠀
• Its average slope is only 12 m over a course 50 km long.⠀
• It was built entirely with dry materials, without the need of any masonry. ⠀
• Stones some of which weigh about 6 tonnes were hoisted 40 m high and maintained by seals carved on site. ⠀
• Only the tallest part, at the height of the canal, is made of rubble-stone fused with mortar.

12/09/2021

ARCH OF PERFECTION sitting under the Pacific Highway.

05/09/2021

STYLISH STRUCTURE ... with a uniform superstructure for the full length of the Harwood Bridge.

🌉 T posttensioned twin U-girders

🌉 a composite transfloor/cast in-situ deck slab supporting each carriageway

🌉 northbound and southbound carriages are supported by twin superstructures on a common substructure

🌉 there a teeny tiny 50mm of separation of these carriageways

Sarcophagus or bridge. I don't blame you for having to think twice.

29/08/2021

EARLY MORNING VIEW of the Grafton road and rail bridge. Certainly a distinguished bridge - its the only one of its type in NSW.

Some interesting facts:
* This bridge is a double-deck road/rail structure.

* It has a lift span to allow river traffic to pass. This is no longer used.

* The lift span is a Bascule span. This was electrically operated by two 35 horsepower (26kW) motors powered by the Nymboida hydro-electric scheme.

* The whole lifting operation took 2 minutes and happened 4-5 times a week.

What a magnificent structure.

22/08/2021

TENSA MODULAR expansion joints. They're used when the movements of a bridge exceeds the capacity of a single gap joint. They're typically used in bridges with movements of over 80mm.

They work on the principle of the movement gap at the end of a bridge deck being divided into smaller individual gaps. These joints can accommodate movements in every direction and rotations about every axis.

No matter what the design or functionality of these expansion joints they always need inspection and maintenance. Starting from the day of installation an expansion joint is continually exposed to natural elements, human effects and animals. Regular inspection and maintenance are critical to ensure the long term performance of any expansion joint.

15/08/2021

MCFARLANE BRIDGE ... a road bridge that carries Lawrence Road across the south arm of the Clarence River at Maclean NSW. It connects the communities of Maclean, Woodford Island and Lawrence.

Harvey Dare, Public Works engineer, designed this curved track bascule bridge around 1900. The design was based on an 18th century scheme by the French engineer-mathematician B F de Belidor.

Only 8 of these types of bridges were built in NSW. This one and only two others survive.

02/08/2021

WILDLIFE AROUND BRIDGES ... carpet pythons come in all different shapes and sizes. I'd have to say a carpet python is probably the most common snakes I see around a bridge.

Summer is python breeding time but surprisingly I've found a carpet snake at almost half the bridges I've inspected over the last month.

You never know that you've going to encounter as a bridge inspector. Bridgedoctors come across everything from giant spiders, angry brown snakes, dozy carpet snakes, bats, possums and wasps. We also run into the odd farmer wondering what we're doing on his land too.

25/07/2021

FORESTHILL BRIDGE ... the tallest bridge in California. It's a magnet for illegal base jumping and a backdrop for "selfies". Its also a great place for bridge inspectors to practice rope climbing techniques.

Despite warning signs social media is overrun with photos of people risking their lives on the bridge. At over 222 metres high it sure is a temptation. Pedestrians can walk along the bridge in both directions ... so watch those urges for the perfect picture!

On one day the Sheriff's Office in Sacramento, California sited three young people trespassing on the girders, two adults hiding under the bridge abutment and rescued a young woman after she fell over 6 metres off a girder. Gotta love a bridge maintenance catwalk.

Thanks for this amazing phone Jen Bartholomew

18/07/2021

BRIDGE PARTS RECYCLED in respect of the long years Tabulam bridge has served its community.

Right up to its last breath the bridge serviced the community... during the building of the new bridge 40 full time jobs were created and 25 local suppliers and contractors were supported.

Truss sections will be used in a viewing platform. From this platform you'll be able to look across the remaining bridge's piers. The piers will stay in the Clarence River for people to forever contemplate and discuss how the longest single span timber bridge in the southern hemisphere met its fate.

Word is there will be some historic information about the old Tabulam Bridge provided near the viewing platform.