Hi
I have to replace a broken string on an ancient upright piano. The action appears to be secured in the piano in an unconventional manner. I have searched for screws that could be securing it but with no luck. It looks as though it might slide out, keyboard and all, somehow. Anyone come across this before?

Photographs would help.

There are uprights that have the action and keyboard slide out together. A clue might be; what does the left pedal do? Does it slide the keyboard sideways or does it push the hammers forward?

Yes, on a few old pianos, the action is attached to the key frame and the whole unit slides out.

However, there are ways of replacing strings with the action in the piano, with the help an expandable tube (cafe style curtain rod).

Many thanks for replies. i'm going there on Monday.

If it is one where the action and keyboard slide out together, the dampers will remain attached to the plate. You may still need Jurgens' threading device or you can remove the dampers as a separate unit.

Many thanks RXD. It's overdamped so I'm guessing the dampers will slide out with the action. But who knows. I've been tuning since the early 1980's and have only come across one other like this, and the action came out after locating a couple of screws

Overdamper. That puts a different complexion on the subject. Something common to sliding upright actions is that the dampers do not move while the rest of the action does. Look for how the dampers attach. To the action or to the frame/plate. What nationality is the maker?

The keyboard sliding is still a clue. I seem to remember something like this but it's all so long ago. I am assuming you are already familiar with the usual ways of securing a birdcage action. A partial removal of the damper system might reveal the secret. (it shouldn't be necessary to remove the wires from their lower locators). Look for something under the keybed for another clue.

While it is always easier without the action in the way, It is also possible to thread steel wire behind the action with no extra tools by simply pre-forming the hitch pin bend and cutting the wire too long initially. Fiddly, with overdampers being where they are, but not impossible.

Action impossible to remove. Tried everything. replaced string by removing damper mechanism. Hope never to see such an awful piano ever again! (Although I almost certainly will)