---
title: "Safety First"
categories:
    - Design Decisions
tags:
    - Safety
    - Top-level design
published: false
---

You might argue that as a type of Nerf gun, safety needn't be much of a concern. Perhaps, but I have two reasons for putting a lot of effort into safety:

1. As an educational aid, I want to be able to demonstrate this safely in schools
2. As a demonstration of modern systems engineering, an integrated safety system is a good example

## Safety philosophy

## Hazard identification

## Safety design


---
title: "Safety First"
categories:
    - Design Decisions
tags:
    - Safety
    - Top-level design
published: false
---

You might argue that as a type of Nerf gun, safety needn't be much of a concern. Perhaps, but I have two reasons for putting a lot of effort into safety:

1. As an educational aid, I want to be able to demonstrate this safely in schools
2. As a demonstration of modern systems engineering, an integrated safety system is a good example

## Safety philosophy

The system should be inherently safe. In its unpowered state, it should not be hazardous. My current thoughts about the design lead to two main areas of concern:

1. A Nerf gun with a high rate of fire
2. A laser

In addition, the system is likely to contain moving parts, low voltage electronics and motors and batteries.

[Inherent safety](https://en.wikipedia.org/wiki/Inherent_safety) focuses minimising the consequences of hazards as much as minimising the likelihood of the hazards occurring.

Taking the laser as an example, it would be advantageous to use a relatively high power laser to shine on the target to make it easier to be detected by the target tracking system. However, a bright laser could be harmful to eyes. It might be possible to use interlocks to prevent the firing of the laser if there is a person in the way, but the system would be more inherently safe if the laser was eye safe. In this case, even if the interlocks failed and the laser shone into someone's eye, no damage could be caused.

In some cases it might not be possible to remove a hazard. The idea of removing the gun component from a gun system is not feasible, for example. In these cases the hazard will have to be mitigated. Mitigation can be achieved through design and through procedure. Design will focus on using features such as [interlocks](https://en.wikipedia.org/wiki/Interlock_(engineering)) and [dead man's switches](https://en.wikipedia.org/wiki/Dead_man%27s_switch), whilst procedural mitigation is achieved by instructions and briefing.

## Hazard identification

## Safety design

I plan to use interlocks in the design.
Add detail to safety philosophy.
Add detail to safety philosophy.
