Some fictitious events in a totally corrupt country...

In an aftermath of exposure of the public disservants and leading government scoundrels, their pervert ways, corruption and lies that were used to manipulate and goad the gullible population into submission and desired action, the people finally understood that they had been screwed, fleeced, made sick, and many dead often after years of suffering or by political assassinations by the government agencies. The realization of the long lasting crimes against the people and the whole nation led into spontaneous civil resurgence all around the country with people of great character as leaders.

             In search of fat pigs

The activity was self financed or sponsored by small and medium size patriotic companies and the masses fed by farmers and fishermen who were still not forced to shut down by the officials. People began to exercise their right of citizen arrest and investigation of the corrupt actors and public hearings were organized to get law and order established. It was impractical and unsustainable to put the scoundrels in prisons as the just punishments often exceeded a hundred years and the criminal would be dead long before the term was over. Therefore, it was deemed more expedient to order a capital punishment straight after the court hearing, without further delay, a decision largely supported. The property of these treasonous parasites was automatically confiscated and transferred into the control of the civil courts and audited and safeguarded by publicly elected wealth managers.

            Bankers seeking refuge in subsea bunkers

From this situation arose a blooming new business, building of gallows and executing the death penalties. Mork was an avid student of the constitution and a truth seeker. He owned a farmland with a saw mill and 100 hectares (250 acres) of pine forest which he wanted to put in a good use. An idea of mobile gallows had long been brewing in his mind, and as the public hangings needed many of these fine instruments of justice, he devised a busines plan. As most of the planks were six meters (20') it was used as design basis. The nooses were positioning at even distances from each other. Because of this the six meter beam would fit five nooses each separated by one meter. As electrical service was decimated and no computers were available to calculate the structures, simple rules had to be used.

Design specifications:

1. Assume a medium weight of a hundred kilos for the convicts. The scoundrels were often well fed and fat, except some rat faced "scientists", "experts" and PR figures having their own peculiar diets and perverted life styles. Using a round g value of 10 m/s2 (deemed more practical and conservative than the natural value of 9,81 m/s2) resulted in 1000N downward force for each.

2. The branchless Northern pine's yield strength is 15 MPa, with safety factor of 1.5, 10 MPa was used. 

3. An ideal beam cross section was deemed to be such that the height (H) was three times the width (W) of the beam.

4. A beam bending stress is expressed with the quotation
Stress = M / S   where M is the bending moment and S is the section modulus
https://mechanicalc.com/reference/beam-analysis

5. The section modulus is calculated by the formula S = WH^2 / 6.
As H = 3W the formula is simplified to  S = 3W^3 / 6 and thus to S = W^3 / 2

6. Without going to the details of the Moment calculation, which can be studied from the web adress above, the maximum bending moment is in the middle of the 6 meter beam M = (-1'000 x 1'000 -2'000 x 1'000 + 3'000 x 2'500) Nmm = 4'500'000 Nmm. For the sake of simplicity the shearing stress in this case was deemed insignificant and thus ignored.

Therefore, solving the required S from the Stress = M / S  when allowable stress is 10 MPa (N/mm2).
gave S = M / Stress = 4'500'000 Nmm / 10 N/mm2 = 450'000 mm3

As defined above it follows, the W = cubic root (2S) = 96 mm, which by the standard beam measures is just 4 mm short of  100 mm (4"). Therefore the main beam cross section  100 x 300 mm (4" x 12") was selected. That was sufficient for hanging five convicts at one time.

The gallows main beam were supported from each end with a  A-shaped triangle and one parallel bracing on one side, fixed to the ground with weights or wedges.

Further Considerations:

It was considered to have about 90 cm (3') slack on the noose rope so that the body could fall freely and cause the neck to break thus avoiding a painful suffocation while hanging by the neck. The convicts were put sitting on a proper height horse or standing on a tall support while waiting a call to their creator and a final ruling.

Other Business Opportunities:

Undertakers and cremators were in short supply during these times. Catering business was in rise as people gathered to have a picnic following the spectacle of delivering justice. Sale of sandwiches and other snacks, soft drinks and alcoholic beverages was easy to arrange for these gatherings and brought nice profits to new entrepreneurs.