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Hello, everyone.

My old Knabe piano will be delivered to my (new) home this Friday, and currently I am very worried yet excited at the same time. (I guess almost everyone here went through the same emotions!)

Even when it is in sad and unplayable condition, it will be nevertheless my first grand piano.

(I wish I can be there when it is being delivered, but I can't... )


Just out of curiousity, does an old piano string pose a danger when it breaks? I cannot get this idea out of my head (piano string hitting my eye, a haunted piano's first stroke!), and I was wondering if I should be careful when opening my piano's lid.


Thank you.

P.S. I will post the pictures!

It can poke you, but they usually go away from the keyboard. (I think Mythbusters was testing whether a broken cable could cut someone in half tonight on one of their reruns.)

Aha! I saw just a bit of that very segment. They did not cut a pig in half with a cable stretched to 30K lbs and cut, but it slapped that poor carcass pretty hard when it snapped.

To the OP, I'd suggest eye protection. I myself need reading glasses so I'm protected when I play my piano.

A piano string stretches very little as tension is applied to it. This means that there is very little energy stored in the string and there would be little or no danger when that energy is released if it were to break.

The steel in piano wire is some of the most elastic material used in manufacturing. A bass string can shoot across a room when it breaks. The only reason it does not happen with treble strings is that they are tied down better.

In over 50 years in the business I have never heard of such an injury.

The known associates of the Gambino crime family state that piano wire has miminal elasticity for their application. and in itself not dangerous

You'll shoot your eye out...

Sorry, just love that movie...

While the wires may be very elastic for steel we are still talking about a few inches tops that the string stretches when it is brought in tune. This is small compared to some other forms of mechanical energy storage like a bow and arrow where the draw force is applied over a couple of feet. While I can easily believe that a bass string (which would have more total stretch due to its length) could have enough stored energy to accelerate its own mass sufficiently for it to travel several feet, it would not have enough energy (velocity) to do any harm to you unless, as you said, it serendipitously impacted you in a sensitive spot with a sharp end, kind of like Ralphie with the Red Ryder.

I can believe that on old string might break while being tensioned e.g. during a pitch raise. But would one really be likely to break during playing?

Have never had a piano string "snap" on me, but I can tell you that when a guitar string breaks while being played, it doesn't snap at you really at all....it kinda just gives way....now that might be partially because your finger is still bending the note while you're doing your best Guitar Hero pose!

I remember breaking a string on an Fender PBass in high school when I was too cheap to buy new strings for it, and it kinda just gave way as well (and I don't remember a snap)....not quite piano bass string, but much thicker than a guitar string.

It happened to me!

Bottom D-flat snapped on a concert grand while I was playing Chopin's 2nd Scherzo - the spot it occurred is at 1:02 in this video of Krystian Zimerman (no, the strings don't break in this video - it is just a reference... ) It sounded like a gunshot and was very unnerving.

I've never had piano strings snap, but they sure scare the snot out of me when I've had them break on my clavichord.

I've noticed that before they break, they can't seem to stay in tune. Then SNAP! and I jump out of my skin when they give way at the tuning pin.

John

I've seen various numbers for the tension in strings, ranging from 180 pounds to 400 pounds. For the sake of argument, let's use 400 pounds.

We'll make the assumption that the wire is stretched to 95% of its ultimate tensile strength (which is probably on the high side), and that the wire is AISI 1060 steel with an ultimate tensile strength of 135,000 psi and a modulus of 29 million psi. Total elongation, assuming a 60" bass string, is 0.265 inches.

The energy stored in the string is 53 foot pounds, which is 70.8 joules.

We'll assume now that when the string breaks it'll transfer all of its stored energy into kinetic energy; this is a conservative assumption in that some will be dissipated as sound energy, some will go into distorting the wire end at the tuning pin, etc., but we'll ignore all that. Assuming (we're doing that a lot here!) the string is 1/16" piano wire double wound with 1/16" copper wire. A 60" long string of this construction will have a mass of about .531 kg.

Based on that, the velocity of the string will be 11.5 m/s, which is about 38 feet per second, which is about 26 miles per hour. That's like being hit by a piano string dropped from a height of 22 feet. It might hurt, if the end is sharp you might get cut, but it's unlikely to do major injury unless it does happen to hit you in the eye.

Smaller, lighter strings will naturally travel faster, but they're still unlikely to cause life-threatening injuries.

That comes from the thinning of the wire when it starts to deform. That makes it stretch a lot all of a sudden, and it is much weaker. Then the string breaks. I hop that those break when I am tuning, because I prefer to have it happen when I can fix it. It does not always happen that way. Sometimes they just go bang.

First few strings I broke on an old upright I used to have...

the VERY first one, I had the bottom board off, and was probably fishing something out of the bottom of the piano, I don't remember. Well, I lightly brushed up against the rightmost string on the bass bridge (right string of B-2 in this case), and it snapped at the end of the hitchpin loop. Funny thing was it just kinda gave way, and didn't go flying. Probably because it was like 90 years old and had totally lost its elasticity.

As for strings not holding a tune before they break, I've had something similar happen once. While I was playing a tune one day several years ago, I noticed middle C was a little more out of tune (like probably a few cents, maybe about 1bps give or take, whereas it had almost been in solid tune just a few seconds before). Next time I played that note, in the same song? *SNAP!*

Am I the current record holder for having broken A-0 (lowest note on the piano) the most times in the shortest period of time? I've lost count of how many times I've broken it. I've spliced it a few times and replaced it a few times, in the past 8 or so years. I also frequently broke A#-0, C#-1, D-1, and D#-1, but not nearly as much as A-0 - maybe about 1/3 as much or so. I've also broken A#-1 once or twice on the piano I had.

" Probably because it was like 90 years old and had totally lost its elasticity." 88Key ...

Yup! Old strings don't fly around much. A newer bass string, on the other hand, is a whole different animal.

I have clients who break bass strings regularly, and so far the strings have taken off away from the player ... so far! Rock-on visitor to western ranch who doesn't know much (dude).

It happened to Horowitz while he was playing Rachmaninov's second piano sonata in a Carnegie Hall recital on Nov. 24, 1968.

After his technician replaced the string, he backed up a few measures from where he stopped, and proceeded to give what many critics consider his greatest performance of this work.

Thread in Pianists Corner Look for the posts by Thracozaag.

Two or three broke at a show I was at several years ago. It was a piano that was about due for retirement anyway. (Longevity was one of the problems with the Yamaha CFIII, and why I appreciate the CFIIIS so much.)

Usually I try to break the strings before the show starts.

In my experience it seems that the strings are pretty stretched out by the time they actually break so much of the tension is already released. This makes it pretty unlikely that any real damage could be done.