About 530mm wide.
In 1962 Bob Dylan wrote a song called “Talkin’ Bear Mountain Picnic Massacre Blues” It’s about organisers oversubscribing a boat trip which then sinks under the weight .
“Well, we all got on ‘n’ what d’ya think,
That big old boat started t’ sink
More people kept a-pilin’ on,
That old ship was a-slowly goin’ down.
Funny way t’ start a picnic” “Now, it don’t seem to me quite so funny
What some people are gonna do f’r money.
There’s a bran’ new gimmick every day
Just t’ take somebody’s money away.”