A spaghetti calorimeter (SPACAL) prototype with scintillating crystal fibres was assembled and tested with electron beams of energy from 1 to 5 GeV. The prototype comprised radiation-hard Cerium-doped Gd\(_3\)Al\(_2\)Ga\(_3\)O\(_{12}\) (GAGG:Ce) and Y\(_3\)Al\(_5\)O\(_{12}\) (YAG:Ce) embedded in a pure tungsten absorber. The energy resolution was studied as a function of the incidence angle of the beam and found to be of the order of \(10\% / \sqrt{E} \oplus1\%\), in line with the LHCb Shashlik technology. The time resolution was measured with metal channel dynodes photomultipliers placed in contact with the fibres or coupled via a light guide, additionally testing an optical tape to glue the components. Time resolution of a few tens of picosecond was achieved for all the energies reaching down to (18.5 \(\pm\) 0.2) ps at 5 GeV.