Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum String scale straight strung Collard&Collard grand

Dear all,


First of all thanks for all the information that is being shared here, I learnt a lot from it.

Now, after doing some reading on the forums I want to ask you experts here some questions.

As a non-piano technician I have been working on a 1875ish Collard & Collard which I got in very bad shape, collapsed and cracked soundboard, non-functional action etc. It is basically a straight strung piano with a full cast iron frame.
I started this as a learning project, to satisfy my curious mind. Currently I am trying to understand the string scale.

Here is a photo of the piano:



The bass bridge:




The piano has been restrung somewhere in the past, it had hexagonal bass strings, I guess they didn't have those back in 1875.
Now, I do not have much confidence in the amount of thought that was put in the string scale when the instrument was restrung due to the condition of the piano.
For example, half of the bridge pins were broken, some 5-10mm into the wood of the bridge. The piano was not playable when I got it, but it must have had huge false beat problems.
One way they dealt with this:



Found some nails as well here and there:




Besides that the wrapping of the bass strings was done very inconsistent:



All of this makes me think it is a good idea to completely redesign the string scale. To start with I put all the data into ScaleRipper, which gave me some nice graphs. The first 8 strings are copper wound monochords, 9-23 are copper wound bichords and 24-85 are plain strings.
Here is a tension graph:



And a break point % graph:



As you can see the patterns are quite erratic, especially in the bass section.


Now I’ve got a number of questions on this:

1. What are the most important parameters to consider when redesigning a string scale?
2. What would be the fundamental difference between the string scale of a modern piano and an antique straight strung piano? Also regarding the placement of the bass bridge.
3. What is a reasonable string tension for pianos of this era? And how should the graphs look like approximately?
4. For the bass strings I read about wound/core diameter ratios which have to be kept within a certain range. What values are usually used? Is there an explanation for this?
5. Can anybody provide me with example string scales for straight strung pianos from this period, and maybe some from modern pianos to compare them with?
6. Is there any (easily accessible) literature that I should read on this topic?

I am certainly overlooking other important things, do not hesitate to point them out as well.


Kind regards,
Harmen

No idea how much you are concerned with cost ? If you look on-line, also on Twitter; -
< Hurstwood farm, Steingraber Phoenix Pianos >.You may find extensive help from them. I and a friend (good pianist but not mechanically inclined) visited said "farm" and looked at numerous pianos which they had rebuilt : plus the first of their own "all-carbon fiber" grand.
On twitter they (HW- Farm), have photographs of a roller type bridge agraffe (sp) used on Steingraber. I would use this if rebuilding a piano. Owner of the business is a Mr Richard Dain -one time mechanical engineer in the Cpper-Belt in what was N.Rhodesia.

I think you have taken on a task which could be likened to trying to rebuild Notre Dame when you have never built a building before.

Jean Louchet _The Keyboard Stringing guide for the restoration of pianos, harpsichords and clavichords_
This is the book you want. I hope you are good at algebra.
Since the piano is worthless as it is, have fun!

If it were me, I wouldn't copy the original. The soundboard has a serious flaw in that the ribs run parallel to the spine. This creates many problems one being that there are too many long ribs. If i remember correctly there were about 5 or 6 that are over 50". I would redesign it so that the ribs are perpendicular to the bridge and only have one long rib and the rest tapering in length. Then with a properly designed board I would design a string scale using a traditional ratios of 7,8, 10. This would work out to something like 160lbs for trichords, 180lbs for bichords, and 230lbs for unichords. With an average tension of about 38,000lbs. i think a general strategy like this is more important than individual string tensions. Which i thick is a flaw to most string scale design software.

And that is just two elements of your piano. Then you got the action to work out. Big job. Maybe as others have insinuated, you should start small and build knowledge and skill before attempting that piano.

Good luck,
-chris

Regarding the string scale, I would also try to find what the actual scale was too, and see what the overall tension was and most likely design the scale to stay close to the original tension. This is a good safety thing to do with regards to the string frame. The Book Stringing Practice by Malcolm Rose and David Law may have that scale.

-chris

Thanks for all the answers!



For me it is not so much about cost but rather about gathering some knowledge on this topic. Besides, the project is going to be a long term project, I am currently abroad for studies for the next 3 years. Gives me the opportunity to disign a wild string scale though..
Thank you for pointing out this type of bridge agraffe, the technique does look interesting. But wouldn't this require a soundboard specifically designed for this?



As I said the idea is more to gather some knowledge and understanding of how a piano works, I do not expect the piano to become as good as a modern day piano built by an expert.
The thing is, I do believe that, alongside reading, for understanding any system it is very useful to actually start fiddling with it to find out how it works. (I am a biologist, this is basically also how biology works)
And yes, I got carried away with it, but it is such an interesting topic.




Thanks a lot for the suggestion, that seems like an useful book for this purpose! I’ll see if I can get my hands on it, this will likely be a challenge here..

Indeed, this piano was on its way to the scrapyard when I got it, there was not much left to destroy before I got it..




Thanks Chris, regarding the soundboard, I did put in a new soundboard with the original layout but with a redesigned rib scale.

Out of curiosity, would it be possible to determine the loading capacity of a soundboard empirically?
For example, by slowly loading it up with some known masses strategically placed along the bridges and observing the deflection of the panel? This would at least give an indication on the maximum down bearing force that the soundboard can handle.

Thank you for your book suggestion as well, I’ll try to get in contact with the authors to see if the info I need is in there. Indeed I think it would be essential to find out what the original string scale was and work from there.


Kind regards,
Harmen

John Delacour, bass string maker in England might have a stringing scale for this old Collard and Collard. I don't know if he might be retired now. http://pianomaker.co.uk/technical/string_formulae/

I found a YouTube video of an old collard and collard straight strung piano. It’s doesn’t sound as bad as I thought it would..

It does have a nice amount of warmth and sustain.

Would sound a lot better if it were in tune, though...

Here is another, restored, Collard & Collard parallel strung. It says 1830s but that's not right - more like late 1870s, early 1880s

Thank you all for the info and the motivating video's.
Unfortunately I haven’t found any information on this type of string scales yet.

Anyways, in the meantime I have been doing some calculations to get an understanding of the string length/diameter/tension relationships etc.

Now I do have a question about the double wound bass strings.
How are they usually wound?


I believe there are 2 methods of how you can do this:

(1) In my case the first and second layer are wound in the same direction, both clockwise looking from the front, and both with the same diameter copper wire.

(2) Besides this, I think I have read somewhere that it is also possible to wind the first layer clockwise and the second counter-clockwise (or the other way around).


In the first case the second wire naturally falls into the groove between two windings from the first layer. So, with the same outer diameter, the copper layer will be denser with method 1 compared to method 2, as there is less air and more copper in the wound layer.
Hopefully this picture explains what I mean to say:




I did some calculations on this. When comparing method 1 to 2, the winding material is 7% heavier and the tension is 4-7% higher for method 1. When calculating the string tensions this can be quite a significant difference I believe.

Now another question I have on this is, how does this relate to string wrap:core ratio?
Would it be better to focus on diameter or mass here?

Kind regards,
Harmen

A while back I published my research notes on Collard and Collard. Two things of interest are:

1) The Collard Brothers had similar (and somewhat confusing names), one was Frederick William Collard, and the other was William Frederick Collard.

2) The pianist and Composer Muzio Clementi was an investor in the company until her retired.

-chris

The history of Collard & Collard, including all the confusing family name ramifications, is covered in one of Dr Alistair Laurence's two excellent little books on London piano makers. I think it is the second one, "More London Piano Makers".

I wonder if John Delacour, piano bass string maker in England, would know suitable string scales.

@ Chris
Thanks for pointing this out, are those research notes still available somewhere?


@ David
The book you mention looks interesting, I'll see if I can get my hands on it.

I tried to contact John Delacour, but I haven't gotten a reply yet. I might try again someday.

I’d suggest trying to find some collard and collard sons pianos or straight strung instruments (original scaling and modified scaling) to find out how they sound in person. Changing the original scaling might take away from the unique sound qualities of the instrument. Sometimes imperfection and historical preservation will provide more satisfying/interesting results than focusing on perfection and “improvements”.

One note: Your soundboard may not be collapsed. It may have been made without crowning. If it seems collapsed, it might not if it were unstrung.

I would second that.

The early history of this company is very complicated, but is summarised in this extract from Wikipedia.


Thus Collard and Collard were a very historic company in the early piano industry in the UK. I would expect that when restored this would be a fine instrument. So far as straight stringing is concerned, my Bluthner, which is just six years younger, has a wonderful bass due to straight stringing - it is rich, clear and incisive. One might perhaps expect this piano to share these characteristics?

I think it was really collapsed, with the strings removed the middle was up to 4-5 mm lower relative to the rim. So it was kinda of a bowl.
Not so strange really, I believe the piano has spend sometime outside in a shed or something. All the small spaces inside the instrument were filled with pine needles when I got it



This is one of the things I want to try. If get a possibility it is indeed best to start from the original string scale.
As there are some english influences in this country, they might as well have left a nice piano somewhere. If only this lock down gets over someday, so I can start looking around...



When looking for info on the internet I do read that more often, a richer and clearer bass in straight-strung instruments. So I am looking forward to hear one in the flesh at some point.