[R-sig-Geo] Conversion geographical coodinate in UTM

[Gilles Benjamin Leduc]

Hi, 

I need to convert some geographical coordinate it UTM. 
First I have a shapefile: 
Front<-readShapeSpatial("ISL_adm0.shp") 
class(Front)
[1] "SpatialPolygonsDataFrame"

then… I tried this after googling: 
DataUTM <- spTransform(Front, CRS("+proj=utm +zone=27 +north +datum=WGS84"))
Erreur dans spTransform(xSP, CRSobj, ...) : 
  No transformation possible from NA reference system

My UTM area is 27 W (If I understood the system) 

What is wrong? 

Thanks in advance

Benjamin