Phase one starts on 1 June with site preparation work.
Work on the concrete foundations starts on Monday and will last until 14 July when there will be a break until 9 September to avoid disruption during the summer.
The scheduled finish date is 23 January 2020.
What is the Network Rail plan?
To raise the height of the sea wall from 5m (16ft) to 7.5m.
The walkway will also be raised and widened to 4m (13ft) from 3.1m (10ft), with a safety barrier.
Why is the work needed?
To protect the line from closure and to reduce flooding of the track by 90%.
Network Rail points to forecasts of a sea level rise of 0.8m (3ft) in the next 100 years.
Western route managing director Mark Langman, said: “world leading engineers” had designed the plans to “ensure the railway line is more resilient to extreme weather and rising sea levels for generations to come”.
What happens in September?
The main construction of the sea wall will begin. Pre-cast concrete panels will be installed, track drainage put in and existing promenade sections will be demolished with pre-cast concrete units installed.
Surfacing work will take place on the promenade with lighting and seating.
How will the new sea wall be built?
New concrete panels will clad the existing wall and this will be filled in with concrete.
Ramps will connect the new raised promenade to the existing walkway levels at Colonnade underbridge and Boat Cove.
When will staff be working?
Round the clock. Typically work will start five hours before and finish five hours after low tide.
Work will be carried out six days a week, but these days will be selected to maximise spring tide working.
What about car parking?
For the duration of the work, there will be no car parking spaces available in Marine Parade, with the parking bays suspended. This will enable them to be used by construction staff to enable the delivery of vital materials.
The parking suspension on Marine Parade will begin on 3 June.
What about access to the beach?
Where possible, “as much access to the beach in front of Marine Parade will be retained for public use” says Network Rail.
During phase one, public access to Boat Cove will be maintained via the footbridge over the railway line, with a pedestrian walkway installed from the footbridge through Boat Cove to Coryton Cove.