Machinery Safety 101

Interlocking Devices: The Good, The Bad and the Ugly

This entry is part 1 of 7 in the series Guards and Guard­ing

Note: A short­er ver­sion of this art­icle was pub­lished in the May-2012 edi­tion of  Man­u­fac­tur­ing Auto­ma­tion Magazine. When design­ing safe­guard­ing sys­tems for machines, one of the basic build­ing blocks is the mov­able guard. Mov­able guards can be doors, pan­els, gates or oth­er phys­ic­al bar­ri­ers that can be opened without using tools. Every one of these guards…

Read More

Interlock Architectures Pt. 6 – Comparing North American and International Systems

industrial Control Console
This entry is part 6 of 8 in the series Cir­cuit Archi­tec­tures Explored

I’ve now writ­ten six posts, includ­ing this one, on the top­ic of cir­cuit archi­tec­tures for the safety-related parts of con­trol sys­tems. In this post, we’ll com­pare the Inter­na­tion­al and North Amer­ic­an sys­tems. This com­par­is­on is not inten­ded to draw con­clu­sions about which is “bet­ter”, but rather to com­pare and con­trast the two sys­tems so that…

Read More

Interlock Architectures – Pt. 4: Category 3 – Control Reliable

Category 3 Architecture Logic Block Diagram
This entry is part 4 of 8 in the series Cir­cuit Archi­tec­tures Explored

Cat­egory 3 sys­tem archi­tec­ture is the first cat­egory that could be con­sidered to have sim­il­ar­ity to “Con­trol Reli­able” cir­cuits or sys­tems as defined in the North Amer­ic­an stand­ards. It is not the same as Con­trol Reli­able, but we’ll get to in a sub­sequent post. If you haven’t read the first three posts in this series, you may…

Read More

The Fukushima Diaries: A Robot Operator Tells All

IEEE Spec­trum’s Auto­ma­tion Blog has run a series of excep­tion­al art­icles on the Fukushi­ma Dai-Ichi crisis since the earth­quake and tsunami occurred on 11-March. Recently they uncovered a blog writ­ten by a robot oper­at­or at the plant that speaks can­didly about the oper­a­tions there and the prob­lems occur­ring as they try to shut the plant down. From the…

Read More

Why you should stop using the term ‘Deadman’

The Dead­man Con­trol Do you use the phrase ‘dead­man’ or ‘dead­man switch’ when talk­ing about safety-related con­trols on your machinery? I often run into this when I’m work­ing with cli­ents who use the terms to refer to ‘enabling devices’ – you know, those two or three-pos­i­­tion switches that are found on robot teach­ing pendants and in…

Read More

Updates to Popular Articles

This entry is part 8 of 16 in the series Emer­gency Stop

We’ve recently updated a couple of our pop­u­lar art­icles! Check them out! Bust­ing Emer­gency Stop Myths Read­er Ques­tion: Mul­tiple E‑Stops and Resets

Understanding the Hierarchy of Controls

The Hierarchy of Controls illustrated as an inverted triangle with each level of the hierarchy written one above the other, starting with Inherently Sfe design, then Engineering Controls, then Information for Use, then Administrative Controls and finally descending to PPE at the bottom. An arrow with the text "Effectiveness" on it runs parallel to the triangle and points downward from Inherently safe design to PPE.
This entry is part 4 of 5 in the series Hier­archy of Con­trols

(Eds. note: This art­icle was ori­gin­ally writ­ten in 2011 and was updated in Nov. 2018.) The “Hier­archy of Con­trols” is one approach to risk reduc­tion that has become entrenched in the Occu­pa­tion­al Health and Safety (OHS) sec­tor. There are oth­er approaches to risk reduc­tion which are equally effect­ive but are less rigidly struc­tured. If you…

Read More

CSA Z1002 Risk Assessment Standard – 60 Day Public Review

Get more inform­a­tion on CSA Z1002. The draft of this doc­u­ment is now avail­able for pub­lic review through CSA.

Read More

Busting Emergency Stop Myths

Emergency Stop on machine console
This entry is part 5 of 16 in the series Emer­gency Stop

There are a num­ber of myths that have grown up around emer­gency stops over the years. These myths can lead to injury or death, so it’s time for a little Myth Bust­ing here on the MS101 blog!

Read More

Five things most machine builders do incorrectly

Five things that most machine build­ers fail to do. With a Sixth Bonus fail­ure!

Read More
All original content on these pages is fingerprinted and certified by Digiprove