Joe Jencks asked about this through Local 1000. Here is the email I sent him.

Hi Joe,
We know that song. Heard Utah sing it at Champlain Valley in '05 and beseeched him for it.

Went to the Mudcat link and there are some errors in the lyric there. I have made corrections below

One important correction that runs throughout is that the "call and response" is a set response, and line 2 is different from line 4 in each verse
The first response is
"Ship gonna sail, gonna sail someday."
The second response is
"Ship gonna sail someday"

The Mudcat transcription has "Ship gonna sail, gonna sail someday" every time. That's not right.

Then the "Workin' on a ship" part is the chorus, always ending with "Gonna build it anyway."

For our rendition we added
"John Brown said, "Let our motto be action" right at the beginning.

Dan Schatz added, at the end:

"Utah Phillips said, "Singing through the hard times,"
        Ship gonna sail, gonna sail someday
"Working for the good times" and "One Big Union"
        Ship gonna sail someday.
–Greg & Terry

http://www.magpiemusic.com

SOMEDAY THAT SHIP GONNA SAIL
(U. Utah Phillips)

Sojourner Truth said, "Ain't I a woman?"
Ship gonna sail, gonna sail someday

Mother Jones said, "No child labor!"
Ship gonna sail, gonna sail someday

Joe Hill said, "Don't mourn, organize."
Ship gonna sail, gonna sail someday

Gene Deb said, "Well, there's a soul in prison!" (union leader Eugene V. Debs?)
Ship gonna sail, gonna sail someday
       correction: Yes it IS Gene Debs, not "Deb" And it's not "Well" it's "While there's a soul in prison..."
We're working on a ship, may never sail on it,
Ship gonna sail, gonna sail someday

Working on a ship, may never sail on it,
Gonna build it anyway.

Marie Sugar said, "Sit down, sit down!"
Ship gonna sail, gonna sail someday
correction: Maurice Sugar, not Marie. Sugar was a famous Union attorney in the early 20th century

Paul Robeson said, "I won't stop singin!"
Ship gonna sail, gonna sail someday

Martin Luther said, "I have a dream!"
Ship gonna sail, gonna sail someday
correction: Make sure you say, "Martin Luther KING". Luther was a different preacher altogether.

Malcolm X said, "Power to the people!"
Ship gonna sail, gonna sail someday

We're working on a ship, may never sail on it,
Ship gonna sail, gonna sail someday

Working on a ship, may never sail on it,
Gonna build it anyway.

Cesar Chavez said, "Viva la Huelga!"
Ship gonna sail, gonna sail someday

Dorothy said, "Swords into plowshares!"
Ship gonna sail, gonna sail someday
correction: It's "Dorothy Day"

Judy Barry said, "No compromise!"
Ship gonna sail, gonna sail someday
correction: It's just the spelling, but it Bari, not Barry

Daniel Berrigan said, "No more atom bombs!"
Ship gonna sail, gonna sail someday

Working on a ship, may never sail on it,
Ship gonna sail, gonna sail someday
Working on a ship, may never sail on it,
Gonna build it anyway.

They're all gone, and we're still building,
Ship gonna sail, gonna sail someday
With hand and heart, and mind and muscle.
Ship gonna sail, gonna sail someday

Working on a ship, may never sail on it,
Ship gonna sail, gonna sail someday
Working on a ship, may never sail on it,
Gonna build it anyway.