From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Failure of a prototype car lighting charge indicator and recommending against its fitment.
| Identifier | WestWitteringFiles\S\2April1928-June1928\ Scan039 | |
| Date | 21th April 1928 | |
| 2- EFC. } FROM R.{Sir Henry Royce} HS.{Lord Ernest Hives - Chair} } (At Le CanadelHenry Royce's French residence.) BY.{R.W. Bailey - Chief Engineer} } C to BJ. WOR.{Arthur Wormald - General Works Manager} PN.{Mr Northey} E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} OWB. C. S.G. REC'D AT WW. & DESPATCHED 21. 4. 28. R1/M18.4.28. ORIGINAL CAR LIGHTING CHARGE INDICATORS. X4008 X.4040 You will remember that I suggested we should not work on the charge control because it added so much complication to the circuits, and responsibility upon R-R.{Sir Henry Royce} However EFC. worked upon it and fitted one to the car I am using. PN.{Mr Northey} told me that Derby said this device could do no harm, contradicting me without my knowledge. Now the experience of this first one is as follows: (1) I noticed it was cutting in and out several times to the minute and I thought it was wrongly set, but it was not touched until one day it ceased to charge altogether and I knew it should be charging, because considerable current had been taken from the batteries. We got no charge for two days, and if we had done much night work the lighting would have failed. As it was I was too anxious to be out long after dark. (2) The following day the contacts were polished and after some success it again failed, and the whole device was taken off the car for examination, when it was found to be loose in the fixing of the contact post, and making bad contact so that no charge was obtainable. Exactly what I fore-saw, and definitely not what PN.{Mr Northey} understood could happen - (i.e. if it failed one was only in the same position as not having it.) Fortunately this happened in the first specimen, but I expected that the contacts would oxidise and the charge be cut off. It will be noticed that as arranged the contacts are not firmly pressed together during charging, but just touch and go. However we have had enough experience to confirm that we must not fit this device. And it follows that something of the indicator type is the safer scheme, and certainly not to interfere with the contacts, but just let the chauffeur know when he is overcharging - (he can so easily switch off.) I believe that the best we know is the so-called green lamp scheme. This is quite dangerous and complicated enough, and also is quite difficult enough to make right, but it is of a type that should do very little harm if it fails - (I mean that it will be hardly possible for it to be the cause of no lighting at night.) It will now be seen that it is too costly not to be guided by our knowledge, and that a certain amount of discipline is necessary if one is to be of any value in a big undertaking. R.{Sir Henry Royce} | ||