Re: [SystemSafety] The Lancaster Floods in December 2015

From: Karuppu Samy < >
Date: Thu, 28 Jan 2016 11:30:28 +0530


It is a never ending cycle of degradation....  

In India, due to commercial power unreliability, every mobile tower is provided with battery backup. There is also a diesel generating set to take over and charge the batteries till commercial power is restored.  

But even this arrangement failed during the recent Chennai floods! The gensets have limited fuel capacity – once the fuel is exhausted, it needs replenishment. Due to floods, the fuel stations were without power and fuel couldn’t be taken out. Even if fuel was available, transporting it to the genset could not be done, as the roads were under water. The net result – many cell towers didn’t operate and the mobile communication was patchy!  

Karuppu Samy  

From: systemsafety-bounces_at_xxxxxx Sent: 27 January 2016 15:10
To: Peter Bernard Ladkin
Cc: The System Safety List
Subject: Re: [SystemSafety] The Lancaster Floods in December 2015  

An example of degrading resilience, from telephony. :(  

Back in the day the old Strowger exchanges were incredibly tough electromechanical beasts (great fun to play with as well). As an example during the Chilean 'big one' a Stronger unit was buried in the rubble of it's exchange building but kept clunking away switching calls happily for a couple of days until the battery wore down. Early Australian exchanges were Strowgers and used to run to huge battery set pairs which alternated between service and charging as the system was DC, which fortuitously also minimised the effect of unreliable mains power on network services. Fast forward to 1989 when we had the Newcastle (NSW) earthquake (I was there it was exciting) and lo our local exchange only stayed up for a couple of hours until it's batteries died. With the rollout of the Australian National Broadband Network you'd think that battery backup for equipment (in the home) would be mandatory...but alas no. So the next major storm, out goes the power and most people's NBN including telephony.  

On Mon, Jan 25, 2016 at 3:44 AM, Peter Bernard Ladkin <ladkin_at_xxxxxx

-----BEGIN PGP SIGNED MESSAGE-----

Hash: SHA256

Roger Kemp has kindly agreed to publication of his short note on the Lancaster floods on the RVS publications page. It is the first item now under "What's New" http://www.rvs.uni-bielefeld.de/publications/#WhatsNew As I say in the abstract, I think it is one of the most important papers on [engineered systems] resilience which I have ever read. It lays important issues out so clearly.

PBL Prof. Peter Bernard Ladkin, Faculty of Technology, University of Bielefeld, 33594 Bielefeld, Germany Je suis Charlie
Tel+msg +49 (0)521 880 7319 <tel:%2B49%20%280%29521%20880%207319> www.rvs.uni-bielefeld.de

-----BEGIN PGP SIGNATURE-----
iQEcBAEBCAAGBQJWpP9xAAoJEIZIHiXiz9k+n7QH/RvPDZb6f4tq/QdANkvakM7G INZFzzOIMDLNcSwJJgEebbYBLIDi0ZkVoPBv2hMau072TBYglGbbJu/idk8ByvRt /NdEId10jQuSn0umEjVms/ky9S2qxOSqvO2RHRyrIMbyqXW9i3NUpc034OXbEflf ECD2eYUB+pn8NdMNAXJy7vgEJ4m8aGxQSqrN6wOZpQCpF1gHaHmCIXkwHFIKZca9 7p7PBufCGMipDCR4fcOmCMUIRr2uhSYM6xXqOmZYs34UMyrd//lLP5jrKg1FgxfM pGC2hbMPpxG58XUw7JYbmLWSNB2g1m7VbBILoHMCu+WGp50ZtukDhmtlqQu43Zs= =rpSj
-----END PGP SIGNATURE-----



The System Safety Mailing List
systemsafety_at_xxxxxx  
-- 

Matthew Squair

BEng (Mech) MSysEng

MIEAust CPEng

 

Mob: +61 488770655

Email: MattSquair_at_xxxxxx

Website: www.criticaluncertainties.com <http://criticaluncertainties.com/> 

 





_______________________________________________ The System Safety Mailing List systemsafety_at_xxxxxx
Received on Thu Jan 28 2016 - 07:00:40 CET

This archive was generated by hypermail 2.3.0 : Tue Jun 04 2019 - 21:17:07 CEST