Tripped up on the way home

As I walked down the street I tripped over an object on the footpath.
Off balance and quite annoyed, I turned back to see what had disturbed my thoughts of a quiet afternoon tea.

A foot long section of footpath was forcibly pushed apart from underneath with a strange navy blue object apparently being the culprit.
I crouched close to the ground to get a better look. The blue object was cylindrical with a six inch or so diameter. It sat proud of the footpath enough to see beneath it. Either end tapered off at 90 degrees, pointing straight into the ground.

As a gap in the traffic appeared, I noticed that the object had a noise appearing from it. I tapped it with my knuckles and heard a hollow, metallic ringing sound.
I put my ear as close as possible without touching the object and could indeed hear a hissing sound.

My curiosity was now fully engaged and I had to find out what this object belonged to below the ground. I ran the three blocks to my house to fetch a crowbar and a cheese sandwich to fuel my new mission.

On my return, a plump man was on his hands and knees with a beetroot red expression on his face. It seemed that he had also tripped over this unknown pipe. I helped him to his feet with great effort due to his rotundity, and we stood looking at the pedestrian disturbing pipe.

As I started attacking the surrounding concrete to get a better idea of this thing, the rotund man mumbled something to himself and disappeared slowly down a side street. For an hour I dug and pried at the fragmented concrete and at length discovered that the right angled sections disappeared into the ground further than it was possible to reach by hand.

A raucous noise suddenly took my mind away from the dig. At the far end of the side street was a black pickup truck with large exhaust pipes billowing diesel smoke out the right hand side. In the driver's seat was the rotund man. As the truck approached, it revealed itself to be a tow truck with a large crane type winch on the back.

I smiled to myself, we were soon to find out what this pedestrian puzzling blue object really was. Without a word, the rotund man and I fastened a clamp around one end of the object and set the winch in motion.

The diesel powered winch caused great strain on the raucous diesel engine, sending outrageous amounts of exhaust smoke into the air.
The suspension of the truck pulled low to the ground and then the blue object began to slowly pull upwards. After five minutes of pulling and copious amounts of polluted air, the object was free of the ground.

The rotund mad joined me again to inspect this newly revealed thing. The sections of pipe which headed down into the earth eventually bent inwards to meet each other and were separated by a square black cube about 3 inches square. On this cube was an orange button, marked 'heironimus ronx'

I thrust through the air with the crowbar and depressed the button.
A previously hidden valve opened on the underside of the top section of pipe. Then followed the sound much like a ship's horn being sounded and then silence.

A tinny voice from nowhere then announced 'heironimus ronx thanks you for your help in the releasing of the shalinumbits device', and used its remaining charge of pressure to blast itself free of the clamp and into the afternoon sky.

My curiosity now satisfied, I went home and made a nice English muffin, while the rotund man drove loudly away to refill with diesel.