The Queen opened the 1.5 mile Kingsway Tunnel between Liverpool and Wallasey on June 24, 1971.
Principal architect Tom Harker was associated with the Mersey tunnels for around 25 years.
The Kingsway Tunnel celebrates its 50th anniversary.
When the bridges at Seacombe Ferry Terminal were first installed, Queen Victoria was on the throne and Liverpool FC were two years from being formed. The giant linkspan bridges are now being replaced after withstanding everything the Mersey's thrown at them for more than 130 years. As part of the £7m project, original cast iron anchors holding the landing stage in place since 1890 were brought to the surface. The anchors are so well preserved they will continue to be used. The landing stage will also be revamped as part of the work that started in December.
The video tolling system will replace the current Fast Tag system used at the Queensway (Birkenhead) and Kingsway (Wallasey) tunnels, modernising the way tunnel users can pre-pay for their journeys.