There's another version (with recording that you really need to hear) at horntip.com

Here are the lyrics posted at that site:

ENGINEERS SONG

An engineer told me before he died
Ah-hum titty-bum titty-bum titty-bum
An engineer told me before he died
Ah-hum, ah-hum
An engineer told me before he died
I have no reason to think he lied
Ah-hum titty-bum titty-bum titty-bum
Ah-hum titty-bum titty-bum titty-bum
He had a wife with a cunt so wide
Ah-hum titty-bum titty-bum titty-bum
He had a wife with a cunt so wide
Ah-hum, ah-hum
He had a wife with a cunt so wide
That she could never be satisfied
Ah-hum titty-bum titty-bum titty-bum
Ah-hum titty-bum titty-bum titty-bum

So he built a bloody great wheel...
With two balls of brass and a prick of steel

The balls of brass he filled with cream...
And the whole bloody thing was powered by steam

He tied her down onto the bed...
And lashed her arms above her head

There she lay demanding a fuck...
He shook her hand and he wished her luck

Round and round went the bloody great wheel...
And in and out went the prick of steel

Up and up went the level of steam...
Down and down went the level of cream

Til at last the maiden cried...
Enough! Enough! I'm satisfied!

Now we come to the tragic bit...
There was no way of stopping it

She was split from ass to tit...
And the whole bloody room was covered in shit

It jumped off her and it jumped on him...
And then it went after his next of kin

It hopped onto an uptown bus...
It's coming to fuck the rest of us!

The last time that machine was seen...
It was in Buckingham Palace fucking the queen

The moral of this story is clear...
You just don't fuck with an engineer!