Insufficient lubrication warning
Evan Zabawski | TLT From the Editor May 2016
I love the smell of aniseed in the morning.
A curious early warning system for insufficient lubrication. (Photo courtesy of the National Railway Museum.)
I WAS PROMPTED TO TRY AN UNCOMMON CANDY after reading Roald Dahl’s Danny, the Champion of the World to my eldest daughter. In the story, Danny recounts how the kindergarten teacher at his school would give an aniseed ball to children who do good work. He describes that the trick is to never bite them, slowly dissolving the candy until arriving at the brown seed in the center, which, when crushed between the teeth, produces a fabulous taste.
Aniseed balls were a staple candy throughout the British Commonwealth during the mid-20th Century but have since become a bit of a rarity. The slow-dissolving candy continues to be flavored by aniseed oil, but sadly modern versions find the aniseed nucleus replaced with a sugar crystal.
Since we couldn’t sample an authentic aniseed, my daughter asked me what an aniseed was and if it was an actual seed. Wikipedia quickly told me that anise is a flowering plant whose fruit is an oblong dry schizocarp referred to as aniseed. A schizocarp is a dry fruit that splits into mericarps upon maturity, and a mericarp is one of the two carpels (female reproductive organ of a flower) that forms the schizocarp of an umbelliferous plant (the family of aromatic, hollow-stemmed plants that includes carrots, celery and parsley). Long story short: not a seed but a seed-containing fruit like the misnamed sunflower seed.
The aniseed’s flavor is described as similar to star anise, fennel or licorice. Fennel is botanically related to aniseed, but star anise comes from the star-shaped pericarp (fruit formed from the wall of the ripened ovary) of a species of evergreen tree, and licorice is a legume like peas, beans and lentils.
Further reading on Wikipedia, under Uses-Miscellaneous, stated that capsules of aniseed oil were incorporated into white metal bearings on British locomotives and would release their distinctive smell upon overheating. This tie to wear detection made it a viable candidate for a column and worthy of further research.
Another entry was found, without citation, for the London and North Eastern Railway (LNER) steam locomotive
Mallard, which holds the world speed record for steam locomotives at an impressive 203 km/h (126 mph). There it stated that the locomotive had previous problems with the big end (crankpin) bearing for the middle cylinder, so it was equipped with an aniseed or garlic “stink bomb” to signal overheating. A third entry, under Steam Locomotive-Lubrication, used the same citation but elaborated further by stating the practice was “customary” and that it warned of excessive heating or wear.
Across the Internet, the citation (Railway Magazine [London: International Printing Co.] 99: 287, 1953) was ubiquitous, but two aspects gave me pause: the lack of an article title, and no usage seemed to be a direct quote, which suggested extensive elaboration or extrapolation from a singular use. Without articles about such a device from any other source, I was beginning to doubt its existence. Finding a picture of the device on the National Railway Museum’s Website validated the premise and functionality.
I found an online bookseller who had copies of The Railway Magazine from 1953, who then located the source in the April issue, Vol. 99, No. 624, and was willing to send me a picture of page 287. The citation appears under The Why and The Wherefore, a section of the magazine devoted to answering reader questions. In a reply to A.L. Holt, titled Warning of Overheated Bearings, it says “A device to minimise (sic) the risk of damage from the overheating of the inside bearings of a multi-cylindered locomotives is used extensively on the Eastern and North Eastern Regions of British Railways [previously LNER], and on certain locomotives of the London Midland Region. If overheating occurs, a capsule containing a strong solution of aniseed or garlic is broken, and the driver is warned by the unmistakable smell of the fluid.”
So I am happy to report that my investigations answered my daughter’s questions and ferreted out a proper citation, while identifying a curious early warning system for insufficient lubrication.
Evan Zabawski, CLS, is a business development/reliability specialist for ALS Tribology in Calgary, Alberta, Canada. You can reach him at evan.zabawski@alsglobal.com.