Preliminary Research and Documentation
Lightning Dissipater
Lightning dissipaters are devices that can prevent lightning from striking boats, buildings structures and seapods.
A lightning dissipater is device that does not attract a lightning strike. It prevents lighting from occurring by making a structure invisible to lightning strikes. The lightning strikes another object (like a tree) or ground and does not harm the structure.
Figure 1 - Preventing a lightning strike using a lightning dissipater
A dissipater is made up of a large number of thin, sharp structures, called dissipation terminals or spikes, placed on the highest point of the structure that needs to be protected. These spikes constantly dissipate small amounts of charges based on the charges in the atmosphere.
When a charged thundercloud approaches the dissipater, the spikes begin to dissipate small amount of the opposite charge, thereby neutralizing the area around the structure. This prevents stepped leaders from reaching down to the structure and raising streamers from the structure to the stepped leader.
The thunderclouds' stepped leaders then look for alternate routes to discharge. A lightning strike occurs away from the structure - making the structure invisible to lightning.
Difference between a Lightning Rod and a Lightning Dissipater
While structurally both are connected to the ground, the main difference between the 2 methods is now charges accumulate and discharge.
In a lightning rod, charges accumulate at the tip of the rod and begin to form rising streamers. This accumulation of charges attracts the charges from the thundercloud, causing a lightning strike.
In a lightning dissipater, charges do not accumulate in one area. Each spike discharges a small amount of charge. Since there is no accumulation of charge, the amount of charge needed to form a raising streamer is very low. Rising streamers are not formed. When stepped leaders descend from the base of the cloud, they do not find a rising streamer and look for alternate streamers that form away from the structure. This keeps the structure safe and makes it invisible to lightning strikes.
Structure of the Lightning Dissipater
The lightning dissipater is made up the following components.
- Charge dissipation terminals (spikes)
- Spike Base
- Spike Ball
- Dissipater Mast (dissipation rod)
Charge Dissipater Terminals or Spikes
Charge dissipater terminals, or Spikes are made up of thin aluminum or steel wires. The are 12 inches in length.
Spike Base
A spike base is a circular metallic that holds the spikes together. The tube is perforated and the spikes pass through the perforations on either side of the spike base.
A spike base is a circular metallic ring that holds the spikes together. The ring is perforated and the spikes pass through the perforations on either side of the spike base.
Figure 2 - Top view of the spike base with spikes