Bridge design for vessel collision. A🧵. The main span of the Francois Scott Key Bridge is 1300 ft. It also has 185 ft of clearance, making this a massive bridge. This type of bridge is considered complex. Baltimore is in for a long haul before replacement. Here is why. 1/x

Thanks for reading my 🧵. I am a bridge designer and professional engineer. I specialize as a design manager for design-build heavy civil infrastructure projects. I post about bridges on X. 8/8

If this barrier retrofit were to be implemented engineers would need to evaluate the effect on the permanent Delaware Memorial Bridge structure. The deck would need to be evaluated for the barrier weight and to resist the forces from impact. 7/8

The temporary concrete barrier would be angled towards the broad face and a guardrail attachment would be placed at the transition to the typical barrier. The temporary concrete barrier, placed deliberately, would now serve as permanent protection for this broad face. 6/

The permanent barrier retrofit could be approached a few different ways. A simple approach would be to place the temporary concrete barrier immediately behind the cable stay. It would be protected by the cable stay (how to protect the anchorage is a different topic). 5/

How do you prevent this? . A permanent retrofit that provides a concrete traffic barrier or guardrail that would protect the exposed face. Recent construction used temporary barrier at this location. The permanent retrofit would be similar, but not reduce travel width. 4/

There is a broad face of the traffic railing is because of the anchorage location of the Delaware Memorial Bridge's suspension cable. This creates a discontinuity in the traffic barrier. The bridge was designed in the 1950 with older highway safety standards. 3/

Bridge traffic railings are not routinely designed for a head on collision from a semi truck at speed. They are designed for forces from angled impacts with geometry that redirects the vehicle back into the lane. The Delaware Memorial Bridge has an exposed broad face. 2/

A crash occurred on the Delaware Memorial Bridge when a tractor trailer hit a traffic barrier head on. The barrier failed and the truck fell into the water below. A 🧵 on bridge design and how this is can be prevented from happening again. 1/

The Eshima Ohashi Bridge in Japan appears to have a steep grade when photographed from far away. However, this bridge only has a maximum roadway grade of 6.1%. For perspective, bridges designed for 45 MPH are allowed to have a maximum grade of 5% and lower speeds are greater.

Demolition of the Howard Frankland Bridge in Tampa begins this week. The new bridge crossing opened for SB traffic in March 2025. Just recently the NB traffic has moved onto the old SB bridge, which opened in 1990. The bridge that is being removed was completed in 1960.

The demolition of the Francis Scott Key Bridge begins today. Cranes and equipment are now being mobilized to the site. The schedule for removal of the existing bridge estimates 9 months. This demolition work begins over 15 months after the Key Bridge collapse from the Dali.

RT @yacineMTB: If I can teach you one thing; it's to never ever doubt your instinct. If your instinct tells you something, it's right. Your….

The historic Joppa Iron Truss Bridge, built in 1907, has collapsed from the flooding in Central Texas.

The flooding in Texas is a tragedy with at least 46 deaths and many more missing. The emergency response rescue effort is on going. The final toll on life and infrastructure is still to be seen. This storm event is at least a 500 year storm. A tragedy. 8/8.

What made the historic Joppa Bridge a special bridge is not because it was a one of a kind bridge, but because it was a routine everyday bridge. It was reliable and cost efficient way to connect communities communities across the United States. 7/8

The top chord of this Truss bridge is in compression and the bottom is in tension. The diagonal struts experience both tension and compression. The patent for the Pratt Truss Bridge was the direction of the diagonals, sloping downward towards the center of the span. 6/8

The Pratt Truss Bridge was designed to be a structurally efficient bridge that optimized material use of the wrought iron or steel. From a bridge design perspective, it was a determinant structure, which simplified the engineering to calculate force effects. A basic truss. 5/8

In the late 1800s and early 1900s the Pratt Truss Bridge was one of the most common bridges to be built. Tens of thousands of these bridges were built across the United States. What made the Pratt Truss Bridge type so prevalent? 4/8.

A bond election was held in Burnet County, Texas in 1906 to fund the construction of three waterway bridges. The Joppa bridge crosses the North Fork of San Gabriel River and it was built near the church and school. This water crossing was the last of the three bridges. 3/8