just had a look again at the Network Rail website for the trackworks due there soon, http://www.ordsallchord.co.uk
The museum atttracts most of its visitors because of the railway. The trackworks are going to leave the museum cut off from the railway network, with about a quarter of its current running line left available.

Let’s just put this in to context…

This is the oldest passenger railway station in not just Manchester, Lancashire, NW England, The UK, or Europe… It is the very first intercity passenger railway station in the world ever! This site is very much responsible for the prosperity of Manchester as a Victorian city, therefore driving the second industrial revolution, therefore driving the sweeping socio-economic changes that created modern Britain, therefore underpinning the strength of the Empire and leading to the founding of The Commonwealth.
There is a section of viaduct that is not listed, this is the part that they are going to demolish to drive the Ordsall Curve right through the site. In doing so, the Grade 1 listed bridge over the Irwell that leads in to the station approach will be separated from the site. The adjacent viaducts which were built slightly later are also scheduled for obliteration, thus removing most of the surrounding historical context.

This will close the museum as it will annihilate visitor numbers.