The whole world is watching Hong Kong, where a battle is playing out in the streets between authorities and citizens protesting China’s encroachment on their independence. It started in June in response to a proposed amendment of an extradition bill that would make it easier for Hong Kong citizens to be sent to mainland China, and has escalated as authorities refuse to make concessions. Now, police in riot gear are marching into crowds of masked protestors with tear gas and water cannons.

In an effort to retain control of Hong Kong Polytechnic University (and the rest of the city), the protesters began crafting gear of their own: improvised catapults, slingshots and barricades. They’re also using encrypted messaging apps to coordinate daring escapes from police, like descending by rope from a footbridge to be picked up by riders on motorcycles below.

On r/HongKong, Redditors are posting some of these inventions alongside updates from within the semi-autonomous city. Many of them are incredibly simple yet effective, like gluing bricks to the streets or driving nails through sections of garden hose.

In some cases, bamboo poles are zip-tied to the bricks to create barriers that could damage the undersides of vehicles that attempt to drive over them. It would appear that the police used armored trucks to break through the barricades, clearing the path for other vehicles, but it seems like it could be an effective way to shut down traffic in other protest scenarios.

Using little more than bamboo poles and helmets, some protesters set up homemade catapults:

Citizens in the streets are also demonstrating novel ways to fight tear gas with thermoses and leaf blowers.

Observers are also reporting the use of drones to deliver supplies to those trapped inside Hong Kong Polytechnic University. Thus far, thousands of people have been arrested, some being transported by train to unknown destinations (which some fear to be mainland China.)

The protesters are also leaving messages to each other and the world using graffiti:

Check out more of the Hong Kong protesters’ creations at Interesting Engineering.

Top image via u/VaelinAISo