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By Joel Stottrup
 Pumpkins were flying as much as 135 yards or more to crash into a hayfield in rural Princeton last Sunday as a Halloween activity for a local church.
The pumpkin stunt was courtesy of local machine shop owner/operator Dan Engblom and the machine he built. The pumpkin launchings drew a crowd of 95, consisting mostly of members of Immanuel Lutheran Church that Engblom attends.
The machine was a trebuchet (pronounced tre•bu•shay), an engine that is capable of hurling objects with significant force. Trebuchets are said to have been used by the French in laying siege during battle in the twelfth century.
Engblom built his trebuchet in his Airway Products machine shop in Princeton with the help of employees Todd Oquist and Ron Haggberg. They built it whenever they had spare time over a nearly three week period using metal materials such as pipe that had accumulated at the business.
Engblom’s trebuchet is all metal except for the ropes and sling. It stands seven feet from the ground to the axel pivot point for the arm that swings in an arc. The frame is eight feet wide and the metal arm has a rope sling attached to a pouch that holds the object that is hurled.
As Engblom explains the mechanism, when the arm swings upward pulling the sling, the one sling rope pulls free of the arm at one point and the pouch hurls the object upward and forward in a trajectory. It’s like the sling shot that David used in killing Goliath, Engblom explained.
Upward and forward is usually how the objects have gone from Engblom’s trebuchet. Sometimes there has been a malfunction where the object has flown backward, though not with quite as much force as when it hurls upward and forward.
But still, the object when going in the wrong direction can cause damage as one pumpkin did that Engblom was using to test his trebuchet two Sundays ago. The pumpkin came down in the wrong spot and broke the windshield on Engblom’s pickup.
Engblom said that when he was asked by someone how his windshield broke, he only responded that it was hit by a pumpkin.
Engblom operated the trebuchet last Sunday afternoon with helpers, Bryce Birkholz, and Engblom’s daughter Brooke.
You could say that the trebuchet is an engine that does not rely on fuel such as gas or diesel to operate. However, some kind of power, muscle or otherwise, is needed to pull the trebuchet’s counterweight up and into place for the next hurl. In this case Brooke drove a pickup truck backward, with an attached rope. The other end of the rope went through a small pulley on the bottom of the trebuchet frame and up to the end of the sling arm to pull it down and raise the 1,000 pound counterweight up.
Engblom would then lock the sling arm and weight in place by hooking a sling arm rope onto the frame with a slip pin. Once that was done, the rope used to set the trebuchet for firing, was detached from the pickup. One of the final tasks was to place the object to be hurled, in this case a pumpkin, into the pouch attached to the rope slings. The pouch, made of old seat belts, was placed on a horizontal ramp on the bottom of the trebuchet frame.
When Engblom was ready to fire, he walked back about 15 yards or so to pull a rope attached to the slip.
Helper Birkholz first blew a whistle to signal there would be a firing and then after looking around, Engblom pulled the pin. Gravity next took over, yanking the counterweight down to throw the end of the sling arm skyward. The end of the sling arm yanked the sling ropes and their attached pouch at first backward and then upward and forward. The pouch released the pumpkin in a high arc over the field to its crash when everything worked perfectly, which was most of the time.
Faces in the crowd followed the trajectory, first up and then down to witness shards of pumpkin exploding outward as the pumpkin met the ground.
Engblom had amassed a supply of about 100 pumpkins, leftovers in a field after a farmer’s pumpkin harvest. A few people also brought some pumpkins on Sunday.
The pumpkin hurling went on for about three hours starting at 3 p.m. and consumed 50-60 pumpkins. About half were in the five to six pound range and the others were 10-12 pounds.
The smaller pumpkins crashed 135 or more yards down field from the trebuchet, while the heaviest ones landed at about half of that distance.
Launching the idea
Building the trebuchet was an idea that grew out of a youth board meeting at Immanuel Lutheran. The board members brainstormed what they could do for Halloween that was different than the traditional dressing up and trick and treating. They wanted something different than the “more pagan symbolism” that is usually seen during Halloween, Engblom explained.
Engblom, knowing about the youth board discussion, began thinking about building the trebuchet to be a main part of the activities. He had the metal materials to build a sturdy trebuchet and once the church adopted the idea, the project began in early September.
His goal was to have a trebuchet that could throw a 10 pound object at least 100 yards. As Engblom put it last week, he wanted to be able to hurl something farther than new Vikings quarterback Brett Favre could throw.
Engblom pronounced Favre’s name like it would sound phonetically, instead of the proper Farv pronunciation.
It was typical Dan Engblom-style to fly in the face of tradition.
In fact, Kevin Beneke, one of the onlookers at the pumpkin launchings last Sunday, had this to say when he was asked what he thought of the whole affair: “Leave it to Dan.”
Engblom did succeed in his goal, in fact the smaller pumpkins landed nearly half again farther than the length of a football field.
Some onlookers seemed to have confidence in where the pumpkins would land. Side activities included haywagon rides and at one point tractor driver Eric Reynolds parked the wagon full of riders what seemed to be a little too close to where the next hurled pumpkin might land. A worried Engblom waved to Reynolds to move the wagon and Reynolds pulled it back out of range.
“I was wondering how good his aim is,” commented onlooker Robert Pringle.
Bystander Merlin Hanson’s sage advice was, “Don’t try to catch them,” referring to the hurled pumpkins.
Engblom, thinking late last week about the growing interest he had heard to watch the trebuchet at work last Sunday, said he thought the whole thing had “grown beyond an attraction for kids.”
He anticipated that a lot of adults, including friends and relatives would show up too, and they did.
“It was a smashing success,” Engblom said on Monday.
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